Haan Hotels with Gym

I was charged more than the agreed price and the hotel refuses to respond to my complaint. I was in the neigborhood and called them after seeing their prices on their site. Based on their offer I went to the hotel, the check-in took a long time because of computer problems. They charged my credit card, I asked for the bill to check it but they said I would get it at check-out. When I complained the next morning they would follow up later. They now deny it and claim I got a better room, but the price of my room on their site is still much lower than paid.