PayPal-22

I accidentally tried to pay a seller through PayPal with an old bank account.  The payment fizzled.  I now have a PayPal balance of -$4.72.

To resolve the negative PayPal balance, I need to pay PayPal with a credit card.  No problem.  I try to add my credit card.  I am told that I have the maximum number of credit cards on my account, and have to delete one before I add another.  I go to delete a credit card, and:

I cannot delete a credit card because I have a negative balance.