Last minute Award flights.
I was once stuck in MSY booked on WN to go to DEN. NW lied to me and told me DEN was closed. I could see flights landing and taking off at DEN because MSY has free WiFi.
After waiting several hours I went to the WN counter and demanded a refund check and got one.
I had already re-booked on FL with a connection through Atlanta using Credits and although I arrived many hours late the hotel was able to get my suit ready for an important meeting the next morning
That was when I lost faith in WN.