If you have such an extremely uncommon spelled last name so that it's close to impossible that someone can write it the right way how did the person know how to write it? In the WoW account website it only shows the first letter of your last name and only a part of the registered email address. We're talking about an over 2.5 years old account so it was still a normal WoW account and not a battle.net account so that you needed the account name and not the email.
So the person who stole it would have to know either your account name+password+last name (and for the last name he would have to personally know who you are and that it's your account) or your email address+password+account name.
I can't really imagine how somebody could know all these things. If it was a trojan virus or something like that which collected all your information about email and account I'm sure your new account would have been hacked very soon. From the WoW account alone somebody would not be able to know your last name or your email address and from your email address alone someone wouldn't be able to know your account name and in most cases it's a lot harder to hack an email provider than a WoW account.
Also if it is true it's over 2.5 years ago and Blizzard has no evidence that it wasn't you. Also if you intended to play some characters later on from this old account why didn't you use this old account for RAF? Why buy a new copy of the game to use it for RAF when you have a perfectly fine account with characters you will play at some point in the future? You could have played on another server anyway, saved some money for the game+BC+WotLK and only manage one account instead of two later on (we're talking about 2009 when we didn't know that there will be battle.net 2.0). Also if you really intended to play on this old account how could you not know the account name and password? If you really wanted to play it again you would have written the account name and password somewhere.
To me it sounds like you wanted to start a new WoW career and thought you could sell your old account when you start a new one. And now that you want to play one of the old classes from back then you thought you can get your account back and transfer the characters to your new account.