Lost parent account

Hello, the new xbox live terms and conditions came out recently and its stopped me being able to access xbox live as i've encountered a problem. When i first started xbox live quite a few years ago my friend helped me set it up, and for the parental account he made up an email and used that, and since then it has been hacked. Because it was a few years ago he made this he cant remember any personal info or the security answer he put down, so we cannot recover it or reset the password. I recently turned 18 and don't need a parental account anymore, but cant upgrade to an adult account because i need to be signed into xbox live which i cant access due to new terms and conditions. This is quite annoying as i regularly play xbox and now i cant access it, can anybody help me?