Keep the reservation. This sounds like a clear-cut $100 to me. I believe the rules require it to be a $100 payment to you, not a $100 adjustment to the bill.

I don't think it's being overly nitpicky to insist on the $100 when you're getting 1 King + 1 Murphy, regardless of the size of the Murphy. Hell, a lot of sofabeds in this world are fulls or queens, yet I don't think anyone considers Marriott to have met the room-type guarantee if a sofabed exists.

I sleep like a rock. I've slept on sofabeds and Murphys and not had a problem. But it's *not* the same as a room with two actual beds in it.

Also a bit frustrating to get that crappy response for the hotel. That makes me *more* likely to push for the $100.