A long time ago, I had a DM try to force my character into a situation like that and I just took over the game for my character.

this is a paraphrase of how it went a lot time ago:

DM: (something like) your character is powerless and chained up

me: I break the chains binding me

DM: you can't, they're too strong

me: (rolls d20). I succeed. I leap at the torturer and begin strangling him

DM: you can't do that... you're still chained up!

me: (rolls d20). The torturer passes out. I take his sword and walk through the door.

DM: (he literally went this way) 6 guards are waiting for you. They attack you. (rolls dice) You take xxx damge.

Me: I cast Sleep on them (rolls dice). They fall asleep. I walk past them..

DM: You cant cast spells!

Seriously... I just ignored the DM and powergamed my way out of his stupid dilemma without regard for rules or whatever he did. At some point a few mintues later, my character was "free" and I left. He tried to badger me days later about "cheating" and "your character was tortured to death". I just laughed and said, "no, he walked out past the sleeping guards."