Reversing a payment that has been done can only take place if the period has not been closed. 

Payment Search Reversal

1. Under the Expense menu, select Payment Search.
   Search for the incorrect payment.
2. Highlight the line and click the Reverse button.
3. This will bring up a warning box. If you are sure you want to reverse this entry, click OK. 
4. This will bring you to the Payment Entry screen with all the reversal details. Check all details are correct. 
5. Enter a Reversal Reason
6. Click Save to action the Reversal. 
7. If you don't want to reverse the transaction, click Cancel to exit this screen.