Advanta Platinum Business Card Usurious interest rates retroactively applied Salt Lake City Utah

I've never missed a payment on my Advanta Credit Card and yesterday I discovered that my monthly finance charge went from $24.21 to $79.29. I made 0 purchases with the card during the last month. When I called to find out what happened, I was told the company raised its rates--from 8% to 25.08%. Outragous as this might be for future purposes, Advanta actually imposed this for past balances! How can this possibly be legal? Luckily for me, I have a small amount of money with this disreputable firm, but what about those who have substantial balances? I immediately found a new card and will transfer my $5,000 balance very shortly.

This was the second "surprise" since I accepted the "15-month, 0% offer." I soon found out that any time I used the card, even though I paid the amount off every month, it was charged as a "cash advance." The only way to eliminate this finance charge was to pay off the entire balance. This stipulation was undoubtedly somewhere in the fine print, but I find it abhorent, nonetheless.

Steve
Madison, WI

Whitenight
Madison, Wisconsin
U.S.A.