One other thing to note is that John Sirabella 
(assuming it's the same guy, but how many can 
there be in the anime world?) is the former head 
of Software Sculptors and current head of Media 
Blasters.  (They are the U.S. company that is 
releasing Rayearth TV and Kenshin TV, among other 
titles.)

So I wouldn't worry about him running off with 
your money.  Most likely he's very busy and has 
lots of email accounts and there was some mix-up.  
Sonia's suggestion to try the phone is a good one, 
and if you get really desperate you could try the 
contact info on the the MediaBlasters site.