I've only had one instance that I remember that a sub asked to be let out early just because he couldn't take it anymore. I think our agreement was 2 weeks and he lasted about a week. This was an online (NiteFlirt) situation and he had to pay a fine.

I've had lots of situations where it had to come off early due to an issue with the device. I don't penalize for that.

In My experience, subs that enjoy chastity are very disappointed when their device has to come off early.