I'm not 100% about this but it seems like it could work. What you need to do is once you have your Main account merged with a scammed account on battle.net and you transfer characters off the scammed account to your main account. You can call blizzard up and make the excuse of how your account got merged into that battle.net account without your permission. It seems like it would make it a lot harder for the person with the scammed account to reverse the transfers when calling Blizzard now that they are not even on the same battle.net account.