I have had that happen before. Are you doing it on the app? I have found that on the full website, I had no issues cancelling reservations, but the app can be very glitchy about it. The mobile site, can sometimes be glitchy too. If you can't access the full website, then you can call them and they will take care of it. I had to do that for one during our trip, and it was annoying because I was on hold for a while- I seriously thought about hanging up and just paying our $30 (3 people) no show fee.