I went through the same thing just to change the expiration date on my card and this is the answer they sent. They answered right away, but I don't need to change mine for a few more days..
From me to admin;
Hi there,
I got an email today saying that my card was expiring and my membership was due. I forgot that I got my new card last month so the expiration date has changed.
Do I need to sign up all over again or can I just change the expiration date for the card?
Thank you
Cyn
From admin to me;
Hello,
Unfortunately there's no way to update your existing credit card information. The only way would be to downgrade your account, wait until your paid period ends (you retain Premium status during this period) and then upgrade it again with your new card info.
Sorry this is so complicated, we hope to have a system that better accommodates this situation in the future.
I hope this helps you. If not just send a message to admin and they will help you out. They are really good about that.. Good Luck..
Cyn