No phone number for shared hosting. They have some ways for people who lease servers though. Phone numbers mean they have to pay people to asnwer the phone, and pay for a multi-line system, and pay for an audio feed so you don't get silence while you hold, and that means you'd have to pay more for your hosting - and that probably wonuldn't bring them a lot of business.
DH tchnical support says 24 hours. You may have to wait that long. Since you seem to be in a rush, did you set your ticket as a "site outage emergency"? They look at thoes faster. but if you can wait, you really should. It's not really fair to claim it's an emergency if it's not.
You may also have the ability to click, "request callback" if your plan inculdes thoes.
yep yep yep. (a search in the forum would have found this answer though)