My site has been down all day with no resolution

My website has been down all day. When I called in this morning the tech was unable to help he asked me to respond to an email I received after migrating to a dedicated server. I did that and received acknowledgement of the support request, but that was at noon.

This is the busiest time of the year for us and use of this site and the reason we migrated to a dedicated server. Now I have been down for a full day. Please help