Well, if it’s your money, tell them you are closing your account, and have them transfer the funds to another (less corrupt) bank/credit union, or take a cashier’s check. If they simply won’t comply, call the police, then and there, to report grand theft.
My father had a similar situation, he won some money on a gameshow, had a check, and the bank it was drawn on wouldn’t cash it! Wouldn’t give him more that $500. He took the check to another bank, and they worked with him. Go figure.