TOS violation by attempting to purchase a game?

Hmm, it sounds like there may have been some sort of account compromise. Please update your password and run a malware scan on your machine. It's also probably a good idea to enable two-factor authentication: http://help.ea.com/en/article/origin-login-verification-information/

As for your issue, please contact support. They can investigate your account more thoroughly, and assist as appropriate. 

http://help.ea.com/en/article/welcome-to-the-new-and-improved-ea-help-center/