I had connected my iPad mini to my net-safe card which creates a virtual debit card and lasts for 48 hours and automatically gets void after that for security purpose. But now I want to remove that information because the virtual card has expired but I am compelled to put some information. It does not have "none" option in payment method which most of the people say that it has. It is related to country?
Finally got it.
As per @duci9y it takes approximately 3 days to complete transaction. Since my transaction wasn't complete, apple was forcing me to put my credit card details. When I put my credit card details the appropriate amount was deducted and then the option "none" was visible.