My SO and I flew SFO-BOS 2 days ago on legacy VX Airbus. Paid extra for premium class when I purchased in May; row 10 on A320. After boarding, noticed we were on an A321 and row 10 is not premium class. Had not received any notice from AS in advance. Mentioned this to FA, she said the flight was to be an A321 since she was scheduled. She summoned a gate agent who came to our seats and told us nothing could be done, and we would be refunded the additional charge for premium class. Another couple in row 10 had the same issue. 2 days later, I have not seen any refund or had any communication from AS. Has anyone else had this problem? Thanks