Journal entry help

Hi, I am having an accounting issue

A customer purchased an item for $500, and then our payment processing company deposited the 500 into our account. The customer returned the item and then the payment processing company took $500 out of our account. What is the journal entry for this? The customer card is showing a -500 that needs to be cleared, the bank account is over 500 and the payment processing account is over 500. How do I get this to balance? What is the JE for this?