I'm a computer tech, and I don't trust e-mail for quick turn around support, I definitely agree with calling. If the tier 1 guy can't fix it and a tier 2 guy isn't in, they'll set up a day for the tier 2 guy to call back. If you happen to miss that call, they'll keep calling until they get a hold of you (not to an anoying point, they will call once, then maybe a few hours later, then give it a couple of days before calling again, but they will call until they get a hold of you).