I can’t remove a gift card due to needed a payment on file but I do not have the gift card anymore so how would I remove it?

You need to understand how gift cards operate. They are not like credit cards which you can remove. When you redeem an iTunes and App Stores gift card it transfers the entire balance of the card to your Apple ID. You then no longer need the card because it has nothing on it anymore. You cannot then remove this balance from your Apple ID other than by spending it.