What are the known emails for support from Blizzard? Is this one legit? Why do they need my cd key now?

An authenticator was added to my account a while ago and I cant login because I dont own one, it probably belongs to some hacker. I contacted support and was replied back from an email addresss marcusk.support@blizzard.com and was mailed by blizzard.com. He asked me to fill out a TOU agreement form and email it back with a photocopy of a government issued id. I didnt do it, and now he is requesting the original cd key for WoW. Is this a scam or is it legit? I just want to make sure it is legit and that my browser hasnt been hijacked or it have been a fake page.