I also have just done this, I think its something ANET needs to look at.. To be fair I was logged into the correct account, but when clicking the link on the main home page Services>My Account - It then auto logs onto your last signed in account, Ontop of that why does it then allow you to add a game code to a account that you already have that game unlocked, I my case I was adding HOT, the account already had HOT...So I just hope that Support can assist, just a long wait... its all very frustrating.