I decided to delete the vendor credit. I  created a deposit from the vendor on the "cost of goods sold" account and matched it to the check. The vendor record doesn’t show the transaction for some reason but the check is in the check register and it has the deposit slip as a match. I put a note on the original purchase invoice indicating there was a refund applied and noted the date so I could find it if need be and the vendor shows a 0 balance.