We once had a river cruise booked and paid for, and then it was chartered out. The company did try by offering us a different cruise in an upgraded cabin. I am sure they considered it a great offer that was more expensive than what we had booked. However, if you want to see Amsterdam and the Netherlands, cruising on the Danube does not work. I finally called and told them we needed the credit back on our card because we intended to fly to Amsterdam and vacation there. (The second part was true, but we did have enough credit.) The customer service representative said she would do us a favor and have the credit back the following Monday. (I called on a Friday.)
They cancelled the cruise for us by chartering it. Yet they though it was a favor to return our payment to our credit card!