how do i fix my billing info if it does not let me select the "none" option?

Everytime I try to update something in the App Store a pop up comes and asks for my password then takes me to my billing info saying there is something wrong. When I first got my phone, when I went through the billing info process it did not give me the option to select none, it wasn't there. So everytime I tried to download something or update something, I couldn't unless I I put in a new bank card everytime. A couple months later an update is released and I download it. I go to update something else and the same thing happens but I finally have the option to click none on whether I want to use a card number or anything for the billing info. Since then, it still happens and now every time the pop up comes out it won't accept when I click the option "none". Once I click "none", I then click "done" to finish the billing correction and now everytime it tells me the billing is incorrect, even after clicking the option "none" in the billing info. What can I do? Please I need help.