Make it possible for your customers to remove credit cards that have expired
When you need to change the payment method for subscriptions, you can only add credit cards and not remove old ones. the old expired credit cards are still listed after a new card has been added and even worse payments cannot be made because your system doesn't check all cards until it finds one that is valid.
Customers should be abe to remove all but one credit card.
Tim Robinson commented
And the instructions for removing credit cards on MSDN do not work with Azure accounts: https://msdn.microsoft.com/en-us/library/azure/dn736052.aspx
And yes, I changed my payment method to a new card years ago.