Sounds like you got tricked bro. Those emails can look very real sometimes but never ever ever follow any links in your email from someone claiming to be Blizzard. They also don't scan your PC for virus.

Scenario probably goes. You got the email- followed the link- got keylogged and they added an authenticator while they clean you out.

Customer service is open 24hrs I think. Sooner you get on it the better!