Well, it could mean emails are ending up in their spam folder, sometimes this happens. I personally have over 500 spam emails a month and it can take a few days to sort through them and find lost emails.
Have you tried using the live chat on their site or maybe calling them?
Well, Mosso is reseller hosting, not a VPS, so you don't have the full control you would like a VPS. You can read up on reviews about Zone.net here, there should be a good amount, overall I read good things about them.
Are you looking for a clustered hosting solution, reseller hosting, or just a normal VPS?