Maybe it was doomed from the start.
We were booked for a six night cruise aboard the Carnival Liberty during Thanksgiving week. Unfortunately, they had a major breakout of noro virus on the preceding cruise and our itinerary changed completely - from six nights to four nights and different ports of call.
We were offered 50% off this cruise and 50% off a future cruise. Also, since we were already scheduled to fly to the port on 11/19, Carnival offered to either rebook our flights (which we figured would be nearly impossible) or pay for two nights in a Fort Lauderdale hotel. We chose to stick to original travel plans and took them up on the hotel offer.