Trying to update OS X

I am unable to update my macbook pro because a window pops up saying, "billing info" is required. I click on the "billing info" button and it then leads me to say I need the newest version of software to continue and click "learn more" The "learn more" button leads me to this website which doesn't help me update. I go to the app store and attempt to update but it leads me back to the "billing info" button, and the vicious cycle continues.