No none option in itunes store.can't refresh my payment details?

I have an iphone here in pakistan. And i use to buy few apps through my visa card.buy sometimes apple would not accept my card details. Even though every things was correct. So i would select the "none" option in options and confirm. And then reenter the same card details and apple used to accept it. But now i don't find the none option for this workaround. I would appreciate alot if someone can help.

Added (1). My details are valid.

Itunes rocks

The none option was removed some time ago because people where trying to get free apps that were not free. All itune accounts must have a valid CC in order to have an account