I feel your pain. I, too, was scammed by Advanta with my introductory rate being 7.9%, jumping to 25.3% for absolutely no reason.
Always paid on time and way over the minimum due. I called to inform them of their mistake and was told they reviewed their accounts and made the adjustment. I asked to speak to a supervisor and heard the same song and dance. When asked for the reason for the increase, she told me she could not give me that information.
Maybe it is because their is NO REASON other than highway robbery! Fortunately my balance is low so I will just pay it off and cut up my card.
Monetary Loss: $100.