Many people complain about being unable to UNLINK their account (after their accounts got unrightfully banned/ reset to lvl 1) but I never heard of not being able to LINK an account.
Contact support and tell them to link it for you. If they can't, then ask them if there is an account already linked (you never know). And if the account is not linked to anything, you could take the actions further.
If you are unable to access the goods you've paid for, then you can try to contact FTC (Federal Trade Commission) and file a complaint. They will guide you through and you will get best results.
I have already commented on the other post with a similar issue; I was fighting with EA for over 3 months as my account was unrightfully banned (I wasn't even playing at the time I was banned). Unfortunately, it was a bit too late to reach out to FTC so I just moved on. But you should tackle this issue fresh ASAP.