gifting a song with a credit/balance in iTunes account?

i have close to a $40 balance in my iTunes account, i am trying to gift a song to someone. it won't allow to me to do it, it keeps saying i have to add a payment method.

i can purchase songs for myself with no problem. but as soon as i try to get it a song it keeps saying i need a payment method....?

i don't have a credit card on file because i keep a positive balance with gift cards.

whats the deal with that?