Barb:

Assuming you are issuing a cheque then the pre-BankRec procedure does not change. Do an adjustment to the customers account to place the overpayment amount in a misc payables account. Now issue a cheque in payables to the customer and record the chq to the misc account offseting the AR adjustment entry. The chq will flow to BankRec.

If doing a credit card refund then record the credit card refund as a negative cash amount in BankRec as part of recording the cc cash batch.