To update your payment information for GoComics.com, please go to www.gocomics.com and log in with your username and password.
On the next screen, click on "My Account." Then, click "Update your billing information."
You'll then be asked to provide your log in one more time to access the billing system. From there, click on your subscription link. This will be a link under where it says “Active.” On the next page, click the edit link by your payment info. You should be able to update the info from there.