Kind of hard to produce something you don't have. If they don't have an empty cabin, they don't have an empty cabin. How hard is that to understand.
I suspect from the ranting, they were not going to be happy with whatever was done for them and they probably were constantly at the Guest Services/phone desk.
We were treated badly after having contracted COVID on a cruise. We dealt with it and moved on. Dwelling on it only makes you angry longer.....