To refund a credit card payment:
In the Account List window, select an account.
Click Payments.
Select Refund.
In the Code field, select the Refund ADA code. An Apply to Charge drop-down field is displayed.
Select the payment you want to refund. A breakdown of the charges is displayed.
Zero out the amount you DO NOT want to refund, leaving only the amount you want to refund.
Click Post. The Undo Payment window is displayed.
Review the information and click Submit.