You'll need a fan account in order to change the credit card associated with your pledge. Once you're logged in, you can update your payment information from the artist's campaign page. Just click the “change payment info” link in the column to the right. You’ll also find a link to change your payment info in your email receipt.
Bandcamp Support is experiencing an unusually high volume of emails from our wonderfully successful fundraisers this summer, so our responses may take an extra few days. We put together a list of common questions to help you help yourself in the meantime - power!