Then custom site is loosely defined. Unfortunately you're very correct about being taken for a huge ride.
The part about no backups is especially astounding. That is beyond inexcusable. I wouldn't even attempt to be nice when dealing with that level of incompetence, nor will I hold back on publicly stating that failure to create backups is a special kind of stupid. Okay no jokes about how I really feel.
Let's look at the positive though. It used to rank, that's good, recovery should be possible providing they didn't do something even more crazy like spam 20 some thousand bogus backlinks all over the Internet (seen that too many times).
Fortunately the Internet Archive may be useful too. Here's a snapshot from the middle of 2011:
http://web.archive.org/web/20110621060255/http://www.jpplumbingandheating.com/