Phone support is probably the easiest thing to do right now. I read from someone that he waited 1½-2hours before he got a hold of them, so the fact that you didnt get a response isnt surprising. But, if Squenix knows whats best for their reputation, they'll send you a new key either to your mail asap, or simply give you a new over the phone.

You could also just send it back to Amazon and buy a new copy (assuming CE is in stock), but that'll be longer than just waiting for them to pick up the phone...