I've been using gift certificates as a form of deposit for a service appointment. I tried to refund a customer who canceled her appointment by selecting 'redeem gift certificate', entering the gift certificate number and the amount. Then I enter the cc info or swipe the credit card to issue a refund on the original card. I get an error stating "Credit Card refunds may not exceed the sale amount. Reduce the refund amount to the sale amount."
I've been using gift certificates as a deposit rather than making a sale of the deposit amount for two reasons. I can use the certificate number to track which clients have made the deposit and when it was redeemed. and 2) if I make a sale of a service that won't actually happen for three weeks, it completely throws off how I'm figuring commission.