MGM Vegas, many years ago. Checked in went to room and walked in to someone dressing..OOPS back to check in desk. The second attempt to get a room was a little better, given new room key and went to the room, opened the door and there was luggage and the room was obviously occupied....back to the desk. We insisted this time for a Manager to go with us to the 3rd room to verify that the room was empty and ready for us to occupy, the 3rd time was the charm. No compensation asked for or offered. I will say, we never went back to the MGM.