Refund Reversals! How do you do them??

This is one I have never had to do before but the current client I am working with requires it.

They make several refunds out of AR which of course creates the AP payment with R12. But what if a mistake has been made or the payment is voided? How do i reverse the refund - i.e. make the receipt available to be reapplied or re refunded?

I have tried the following - all either create errors or simply don't work

Deselect the 'apply' button against the refund

Cancelled the AP invoice

Voided the AP payment

Tried deleting the Receipt