What I have done is create an AP vendor called REFUND - when I have to refund a customer, I adjust the credit amount from AR through a cash batch to a holding GL account and then enter an AP under the AP vendor REFUND using the holding GL account. Our REFUND vendor has a memo to always pop up to alert data entry to update the REMIT to address for the check. We rarely process refunds so we can only have one invoice entered at a time and that works for us. 

What I have done is create an AP vendor called REFUND - when I have to refund a customer, I adjust the credit amount from AR through a cash batch to a holding GL account and then enter an AP under the AP vendor REFUND using the holding GL account. Our REFUND vendor has a memo to always pop up to alert data entry to update the REMIT to address for the check. We rarely process refunds so we can only have one invoice entered at a time and that works for us.