I have a very serious problem

I have decided a while ago to migrate 12 subsites of http://www.baicu4design.com to http://www.catalinbaicu.com which both are wpmu. Problem is that all those sites migrated are moved to this server with huge problems in the last 12 hourse since all subsites under catalinbaicu.com are down! now I had enough of excuses and no solutions coming from this bad experience i have with this new server which is namebox.ro and I want to move back the sites to the new server in fact I wander if there is a way to move back all subsites from catalinbaicu.com to baicu4design.com. I have already a backup created in my wpmu dev account on the catalinbaicu.com. Problem is I dont know how to do all this and I also dont know if i can use a backup from another wpmu to another wpmu. Please help me since ther ar already 12 hours since my clients sufer from this rubsish server called namebox.ro