Originally pre ordered this game and decided to come back and give it a shot. However.....
Log in on forums: works
Log in to game client: works
Try to log in on main website: says " account doesnt exist"
I mean if Zenimax doesnt want my money to upgrade my account thats ok. I can go play a different game.
Also....yes I clear cache and yes I tried on Chrome, Safari, and Internet Explorer. Clearly a problem on your end