Payment
cant seem to remove a method payment and use my iTunes card need help?
Question marked as
What happens when you try to buy something ? You can't specify how items are paid-for, it's automatic, whether or not you have a card on the account should be irrelevant.
Changing/removing payment info : Change, add, or remove Apple ID payment methods - Apple Support
If you don't get the 'none' option on the payment details screen : If you can't remove your last payment method or use no payment method with your Apple ID - Apple Support