HELP! My EA account was hacked!

My EA account was hacked... This is a long winded story that I wish was shorter but ill do my best to explain. 

Back in 2011 when I was a child I made an Origin account which in now a regular EA account, and I do not remember a lot about it because it was so long ago. A few years back I logged into the account and a lot was changed but I hadn't been on it for a while so I just didn't think about it. Well recently I logged back in because I got a code for BF6 and I really want to play it but I can't access anything with the account unless I log in through my linked Xbox account. I took pictures of everything I can and have proof that its mine but when I take it to EA tech support they can't help me because they cant verify that its me and if I want to verify that it is me I have to wait 3 hours each time until I get accepted.

I am very frustrated with the whole thing and I honestly just want my Xbox account unlinked so I can add it to this account and don't have to worry about it anymore but I can't even do that without permission too. I emailed the account holder and it got bounced back because the email no longer exists.

I have no idea what to do and I really want to play the new BF6 but I feel like I am fighting an uphill battle.

Can anyone help me?