well.... i had almost the same thing happen to me.
Execpt I had only paid for training and not gotten started yet.
I went and found the shop owner (small shop with him as pretty much the only employee) and found out what happened and asked for my money back. Well of course he wasn't rolling in cash (otherwise he wouldn't have closed his shop) and said he was teaching a class next month of students. I agreed to take that class. After all he was still an instructor...
Well I completed the class with him, but if I had to do it again, I would have just gotten my money back. It did irritate me that he didn't bother to call anyone who paid and let them know he closed. I had to go search him down at his other job (he was a firefighter).
Due to his economic situation, he really didn't have a decent selection of rental/class gear and it was sorta all mix and match.
He also didn't teach the full curriculum of the class. (we didn't know this at the time as we could only go by what he taught us).
Now every instructor is different and hopefully you won't have these problems. But it seems you can't get him to return your call.
NAUI has a quality control group. If you can't get him to return any calls, then call NAUI and file a complaint against him.
I doubt NAUI can get your money back though.
I'm betting you'll have to do small claims court for that.
In the end, if the guy still gives you hassles and won't refund your money, post the information here and at least it might help a few others from getting taken by him.