I can rewrite the text for you. Here it is:
We arrived at the hotel around 2pm and checked in. We were informed that early check-in was not possible, which we understood. We left our luggage at the hotel and went to the job site. However, when we returned to the hotel, we were told that there were no rooms available, even though we had a reservation and had already paid for it. This was very frustrating for us. After waiting for a while, the hotel staff sorted out the situation and we were finally given our rooms.