I'd go to another hotel.

Edit: Actually, if the wedding party is "coming in" and not there yet, I'd simply insist on the room you booked. They can bump someone in the wedding party. As globalist you should be able to get this. I would not wait until the next day. If the front line employee can't handle it, insist that they get someone on the phone who can. If that means calling the manager at home, so be it.