It strikes me as rather bizarre as well. I just got off the phone with Choice Privileges support who said that they don't see anything wrong with my account but that they are unable to do the transaction over the phone because they sell points through points.com. The strange thing is that I used 4 different cards, cards that I use regularly and have used without issue since then. Maybe I'll try to call points.com, but at this point I don't know if its worth the hassle.