If the room in this case is already prepaid, $71 x 2 nights plus taxes equaling around $170 the Ren has already got that money.
If I don't show up the night of my stay, Marriott had already got paid and will resell my room.
TrojanHorse, in the case of the disastrous over charge I was given a "sorry but there is no way we can reverse it, realize we all make mistakes". It flat out SUCKED!