Update an existing account

Ok so I just receive my code for the CE digital game, but I already have an account because I played since 1.0 (not legacy) and also played at the early release, so how to I link the code form the CE to my existing account, because in the SE account page it says upgrade to CE but that only gives me the option to pay, and the page to redeem bonus item codes gives me an error when I input the serial number.

Anyone know what I need to do?

Not sure. I'm completely lost on this as well and haven't been able to find any info on it. :/

Bump anyone knows?

Bump, sorry but I really want to know because I pay for that extra content ^^;

Any new information about this because I have seen posts of people creating a second account and I don't want to do that