My I tune gift cart is in valid
I try to activate my Apple ID by using a gift card but it said it is not valid
If they page that you posted from doesn't help then you will need to try contacting iTunes Support (these are user-to-user forums) : http://www.apple.com/support/itunes/contact/ - click on Contact iTunes Store Support on the right-hand side of the page, then iTunes Cards And Codes (you will probably need to give them images of the front and back of the card, and possibly its receipt)