Call your state's labor department, with evidence that you were asked to do OT and you let them know such. The state will come down on them and force them to pay. A friend of mine got a very nice (10K+) check from the state for this very same situation.

Talk to your bank - USBank protects debit cards to the same standard that VISA does for credit cards (which, since USBank debit cards usually double as VISA-network cards, works out well). In fact, a lot of banks these days are stepping up to the plate and saying that they will not hold you accountable for fraudulent charges.