I made an account and put "none" on my payment option and I downloaded a few apps and a few days ago I tried to download another app and it just keeps telling me to fill in my payment information, and whenever I fill everything out it says "For assistance, contact iTunes support at www.apple.com/support/itunes.ww/. (http://www.apple.com/support/itunes.ww/.)"
ah i see the problem, you are using itunes.