This has happened to me. I booked a last minute award ticket from BRU to LHR on BA. BA cancelled. I called AA to get a refund. They gave my miles and taxes back, but wouldn't refund the ticketing fee.
In this case it was an AA flight that was the subject of a schedule change. It was changed to be earlier than we could use and in fact I would not have made the entire transaction if that was the proporsed time of departure.
This was a truly negative expereince and opportunistically usurious by their own hand.