Refunding the Purchase of a Gift Card
From FloristWiki
You can issue a refund for the purchase of a gift card as long as the gift card has not expired and the balance on the gift card is equal to or greater than the value that was loaded on the gift card at the time of the purchase. When you refund the purchase of a gift card, the value that was refunded is removed from the gift card.
To refund the purchase of a gift card, you must cancel the order in the Point of Sale window. One-Click refunds are not available for orders in which gift cards were purchased.