Only book one room at a time
I booked two double rooms, one 11 months out and one 8 months out. I confirmed with them that the rooms were good since they were checking I didnt accidentally book 2 rooms.
2 weeks before they tell me that the single room wouldn't be available and wanted to see if we can take a triple room. I never booked a single room but was told that even though I paid the price for a room with a double bed because it was a single traveler they were going into the single room.
My mom rebooked herself into another hotel and let them know, waited a few days and they never cancelled my mom's room, not sure if they were hoping I forgot and they could keep it, they were surprised when I cancelled it asking if I was still planning on staying there.
I ended up getting a triple room even though I just wanted the double, not sure if they were planning on sticking us both in this room and collecting the fees for 2 rooms.
Later when checking out the 'locked' room with my bags was unlocked and the door was wide open, I walked out with my bags without telling anyone.
If you are a single visitor and want a double room, say you have two people otherwise they will downgrade you.