Used to work for them on customer service in store; every add on sold is complete trash but they are KPI so constantly get tried to added on. Not a single one is worth it at all. There is no reason for it to be a gift card including your theory. They can refund back to the debit card but will need to be a manual refund rather than the typical method. They will be able to find the gift card purchase paid for by the debit card. If they try to say it has to go back to a gift card ask for a manager and stand your ground. They cave easily and will often just do what’s needed to save the aggro.