Do as kikichan said. If it's your account, you can send and email telling Acclaim you got hacked, but from your original email address, if you don't remember it (which can happen if you got multiple accounts and don't keep a log) then you can't do much.
But if you wanted to buy someone else's account with either DIL or $$, the only thing you can try to do is get the other guy's account banned for account sharing. Taking screen shots of account trading conversations in-game and telling the guy what you'd do if you were to get scammed, is a counter measure for this type of cases. That's from my experience because I got scammed too trying to buy an account with DIL.:o