Reverse happened to me in Conrad Singapore. I was given a room key to someone else's room
Second was cleaning staff in the Doubletree in Penang, kept leaving my door open after cleaning the room due to dodgy deadlock. Quick scary.
Both Pretty bad I thought.
I got a box of chocolates to say sorry from Conrad and offer of dinner in Doubletree. I wish I'd asked for something else - they did say, let them know next time I am staying and they'll do something.
Needless to say, I haven't been back to either when I've been back in both places.
Issue is a Hampton can't really do major comp, but comp the room.
Does sound traumatic though, but hopefully OP sees the funny side and has a great hotel horror story to tell in the future.