i think this kb is very old, not useful anymore.. I cannot see any reset button in this page.. http://store.apple.com/uk/account/home
Resetting iTunes Store warnings not working.
iPad 2, iOS 6.1.3
That button isn't on that page, the article refers to logging into your account on your computer's iTunes via the Store > View Account menu option e.g.
The button should then be at the bottom of your account's page