When you say they bent the bolt of the deadbolt, the actual bolt or the cylinder out of the door frame?
I've forced alot of doors in my day and can't recall a time the actual bolt was bent, usually the cylinder or the door frame gives up the ghost first. Are they steel frames? Wooden frames? On alot of doors there is enough "spring" in the frame that you can flex the frame and the door will pop open and have very minimal damage... I've forced open doors will a halligan bar that have locked right back up like nothing happened.
Doors are pretty weak generally...
I'd second the recommendations about reinforcing the door jam, maybe a deadbolt with a longer throw, you should be able to goto a locksmith and get a deadbolt with a longer throw keyed like the current one, I had this done at a rental property before.
The Ultimate Deadbolt Door Test
Interesting results here...
Armor Concepts Ultimate Door Security and Window Security - Sliding Door Locks
Something else to consider are the hinges... Right behind the lock, they are probably next weakest... I'd look into the hinges that have the "pins" on them that mate into the hinges when closed for extra strength.
Sent from this... Using that..