Ibis budget Hotels in Mauguio

As I was trying to make reservation with this Ibis Budget Montpellier Aeroport Parc des Expos, based in Monteppelier, France, a number in a USA would be available for making reservation. I've talked to the attendant that at first showed to be very respectful and calm. After I've given all my bank and billing address details and paid for the first of the two rooms, the attendant asks me to wait for 1 or 2 minutes, when we resumed the conversation, he said the price for the second room had increase $5 and that this was the hotel normal price policy . After arriving at the hotel, I ask at the reception about this price policy fluctuation as they refuted that possibility, since the price change may occur daily, but not anytime of the day (especially since you already started your reservation, since the client cannot have access to the price table). When I received the receipt, first, my billing address is was located in the US and live in the UK, so is my address (although I've giving the attendant all my personal information). The price for the service was not clear ahead and I ended up pay an abusive amount of U$27.76 of U$87.24, while the actual price for the room was only U$59,24. All in all, I felt cheated, the food was not looking fresh and burnt for the price of €41. Besides that, I've tried to contact the hotel and the agency that made the reservation and simply I couldn't get through to any of them. Quite frustrating. No plans to use their service in the future.