Here at SubHub we take security very seriously, which is why we do not keep a visible copy of your payment details.
If your card expires or you want to use an alternative card, you can log into your SubHub account here - https://www.subhub.com/static/login
Use the email address and password you signed up with, or request a password reset if needed.
Click on the 'My Account' drop down, and then go to Add Card
Add your new card details and then hit save.
Delete the old card and then save again.