I'm going to try to keep my head calm while writing this... but it's a topic that I feel very strongly about.
My absolute least favorite method of "punishment" in D/s is cutting a sub off from D/s. Occasionally I read about situations that use this choice or read people recommending it. I think this is one of the worst possible solutions and back in my courting days, if I read/heard whatever about a Domme that was in favor of this method, I stayed the hell away.
For a sub in a lifestyle D/s relationship, think of submission as a second career, a relationship, regular therapy, a drug addiction, a moral compass, and their hopes/dreams for the future all rolled into one. Abruptly cutting this off from a sub can be emotionally shattering and most subs are confused enough about the roots of their submission.
That's not to say that there aren't times where I feel this is an applicable solution. I just think it's a very drastic one that is only effective when it's been negotiated beforehand or as an absolute last resort. Too often I see it championed as an "easy out" of a complicated situation.
Developing a functional daily D/s dynamic takes a lot of work and a lot of trust. Fostering it takes a great deal of understanding about both parties. To me, ceasing D/s is the equivalent to a separation in a marriage: things may reconcile but there is a massive amount of damage to be repaired to bring it "back to life." As such, I can only see this being a viable option in severe cases of breach of trust, on a similar magnitude to events that may trigger a divorce or separation in a vanilla relationship.
Healthy couples generally don't threaten divorce or legal separations lightly. This isn't a reaction that should be something that comes up easily. In a functional D/s relationship, dominance is as important a part of the Domme as submission is to the sub. If shutting down the needs of both parties is the best solution, the infraction causing this should have been of relationship-ending magnitude.
With that in mind, both Dommes and subs are people, full of complex human emotions that will change on a regular basis. Dommes may not always feel dominant. While subs are almost always submissive, their willingness and enthusiasm for the daily grind may ebb and flow. This is natural. Life does this. When I hear about situations considering a cutoff, it is often accompanied by thoughts along the lines of, "I didn't sign up for this, it's too much work."
Something to keep in mind is that the more submissive a sub gets, the more easily he can show love, but the less able he is be able to convey any negative feelings openly or in a constructive manner. Think about that sentence again. Subspace can be a trap and a shackle at times, when it runs deep, the desire to avoid upsetting the Domme can outweigh his desire to communicate openly about problems or concerns he may have. If that submission isn't encouraged/reinforced regularly, there will be a natural tendency to act out a bit in order to instigate a reaction that will bring him back.
This is where it's extremely important to have regular communication sessions where the sub is not in subspace and the Domme is in a positive state of mind (e.g. it's not a good idea to have these when a Domme is feeling down). It's up to him to be honest and voice his concerns. It's up to her to decide if those concerns are valid. That may sound harsh, but given a chance to communicate after being immersed in subspace for a long period of time, a sub may mix his "ideal fantasies" in with actual issues. Voicing his feelings will relieve the sub of his building internal pressure, but how a Domme decides to process and use that information is based heavily on experience.
A natural question in these types of conversations is, how does a Domme punish a sub that enjoys fairly intense things that are often considered punishment?
This varies greatly from case to case, but I think it's important to understand that many of a sub's preferred "activities" are very environmental and not just the activity itself. Changing the environment can often make something a sub desires turn into his personal nightmare. If a sub gets off from a sensual over the knee spanking with caressing, T&D, and sexy verbal play, the punishment version of this would be bending him over a table, skipping the warm-up, and unloading a savage belt whupping without any positive or sensual words. In other words: hit with the intent to hurt. If a sub loves being bound and teased, the punishment version of this would be binding him and then dumping him in a closet or the basement and leaving him to stew. It's one thing to be tied up in the bedroom for play, it's a whole different game when there's nothing sexy about it, you have no idea when you will be released, it's cold, she's nowhere near you, and there's icy hot on your nipples and balls, you might have to pee, and so on. If the sub is a sissy that enjoys serving in a private setting, send him out to mow the lawn and make sure he waves at anyone that might honk or shout.
Basically, there's always a way to make something suck. There's always a way to twist something into an unpleasant form. Usually, this requires pulling a sub outside the bounds of their Femdom fantasy realm and delivering some of the same activities in a new, awful package.
This takes some work, but compared to repairing a damaged relationship, it really takes hardly any work at all. 99% of the work is mental, 1% requires actually doing something. How much time does it actually take to chain a sub up in the basement? 3-4 minutes if you make him fetch the chains? If a Domme is down on their sub's behavior, I can understand why they might not want to have to brainstorm ideas for behavioral correction. At the same time, I know there are many Dommes that naturally come up with far too many (and too harsh) of ideas for punishment. These Dommes are usually very willing to assist with ideas.
In a perfect world, this sort of thing should never have to happen. Unfortunately we are all human and all have flaws. For a sub to act out every so often is predictable if the dominance that keeps him focused and in line isn't constant. He won't be able to say, "I'm not feeling right, I need some dominance to get my head straight," until the rebellion is well underway (unless there was a specific regular time for him to communicate appropriately).
It's common for subs to have passive-aggressive ticks that signal this is starting. These are usually things they never forget or balk at. Look for the signs, did he address you properly every time he spoke? Did he perform his rituals perfectly, crossing every t and dotting every i? Do you feel he is testing the limits of your dominance and patience? If he fails the answers to these questions, it's not a mistake. I wouldn't say it was intentional, more subconscious. Think of him more like a child that doesn't know how to understand their feelings so they act out. In subspace, a sub can't communicate rationally as an equal, because he's not, so his mind does what it can do, which is to rebel on a small scale.
The best way to deal with a rebellion? Squash it... immediately... by force. A swift and harsh action should be enough to bring it down and return the sub back to the subspace he is needing. This can be as simple as an order to go kneel in the corner or as brutal as a beating that will leave him bruised for weeks to come. I trust the Domme to know which course of action is best.
I am not immune to this type of behavior at all. When I feel it's happening (or am told it is happening) I feel a great sense of shame and self-hatred. I feel weak and angry at myself. I feel like I have disappointed the love of my life and it hurts. Punishment feels appropriate and puts me back to where I NEED to be.
Returning back to the overall topic... I just really think there are nearly always better solutions to problems than cutting a sub off. If it's bad enough where cutting him off seems like the best solution, that's probably bad enough to kick him to the curb in general. If that seems too extreme, then whatever he did probably isn't worthy of this. Remember that he put his trust in you and trusted you to lead the way. If it becomes too easy to yank the rug out, so easy to give up on his submission, is it even worth it? Or is it worth working to change things so that it will never happen again?