Apple I'd payment option can't select none?

Ok this is my problem I had a credit are on my apple I'd but my mom changed her credit card so this one on my account is invalid but every time I try to update an app or download a free one it says that I have to enter a credit card I'm using the iPhone 4S and its on the latest software. I've tried to take the old credit card off but I can't choose the none option for payment options

You have to have a valid credit card on file to use it even if you are owed a credit.

Apple ID Support http://www.apple.com/...t/appleid/

Manage Apple Account http://www.apple.com/...id/manage/

If you have time go to the apple store they will help.