"I would like a written apology and perhaps the Tropicana can offer to make it right by offering us a stay in the future at no cost."

I am sooooo sorry you had a problem at the hotel.
There's the written apology, and mine is worth more than the hotel's because it is completely heart felt.

They already made it right by comping the hotel.

"unless the hotel offers something spectacular to win our business back."
You must be the greatest customer in the whole world to make a statement like that.