I don't know if this will help, but...

1) Try and do a dummy booking for your same hotel for tonight. Can you get a room? Show the reservation to the front desk.

2) Did you go down to the front desk to get the manager on duty? It's easier to dismiss you over the phone than in person?

3) Ask them to find you another room in a different hotel. Like being walked. (I don't know if this is allowed.)

4) Find your own room in a different hotel, check out of where you are and go there.

Good luck...let us know how this works out.