If you believe you have been the victim of a crime the thing you do is call the police. When the OP "told them they didn't want to press charges" all leverage was gone. Hotels are not police authorities and there are limits to what they can do. Even if they show someone going in the room that probably wouldn't be enough to "fire" the employee, they would have to tie that to the use of the card and when you took the police out of the equation you tied everyone's hands.