If you go to Reports > Payments Report, you may see the option to refund a guest if the status is set to Unused.
The Unused status will appear for a gift card transaction. You can also see an Unused Payment error on the guest's Timeline that you can see Why does the guest timeline show an error for "Unused Payment"? for more information.
When you hit the Refund button on this page, it sends a call out to the payment provider that a specific gift card needs a refund. The payment provider takes it from there on their end since Punchh does not process Gift Card payments. See What Gift Card/Credit Card processes are not controlled by Punchh in the app?+
If further assistance is required, submit a ticket to Punchh Support. (For help submitting a ticket, click here)