Do you have a name and a mailing address? If so, you can look up his phone number here:
http://www.anywho.com/
I've done that before with bad sellers, and I can tell you that they're always VERY surprised when they answer the phone and it's me, grilling them about where the f*** my are my parts?
It's very, very easy to ignore emails. Not so easy to ignore a real person on the other end of the line.