How can I spend the credit on my Apple account
I've recently purchased a new iPad and as part of the deal I was given some credit my my apple account. I'd like to use this credit to purchase a film, but the iTunes app wants to charge my debit card instead of using the credit I've got.
Initially I didn't register a card with the iTunes app, but it kept insisting I register a card. Eventually I relented, but I registered a debit card for an account with very little money in it - less than the price of the film. This is OK because the credit I have in my Apple account will easily cover the price of the film. Now when I try to buy my film iTunes says that the purchase failed and my on-line banking app for the Debit card says that the transaction was declined because there wasn't enough money in the account. This is all true, but ITUNES SHOULDN'T BE TOUCHING MY DEBIT CARD.
How do I actually send the credit I've been given?
iPad