This explains my cancellation. I booked two flights to LAS, one from DTW and one from FNT for June. For the return, the FNT is the day after the DTW return, so they aren't duplicates, but the departures are. They are all booked as one-way and on points. Last week, I cancelled and rebooked the DTW-LAS for a refare. Two days later, it was cancelled without explanation. I rebooked it last night, but now I wonder if it will be cancelled again.