Q: I would like to make an in app purchase using my $20.00 credit that I have on I tunes. I am using my  i phone5. It does not give me the choice of using the credit that I have, only a credit card. How can I use the credit for the purchase??

I would like to make an in app purchase using the $20.00 credit that I have on itunes. I am using my i phone5. It does not give me the option of using the credit that I already have, only of using a credit card. How can I use the credt that I already have instead of a credit card?