hey im really sorry about this (it just pisses me off when i hear crap like this happening)
i did a little digging so apparently he has his domain registered at
Schlund and Partners where you may speak with the registrar and see if they can take it down. Tell them about the agreement and try to obtain his address.
he is also paypal verified under the name,
support@pocket-nano.com, so they also have his address. following the filing of complaints, they may give it to you.
you might want to fill out a form at
http://www.ic3.gov/ and
Federal Trade Commision or call 1-877-FTC-HELP to get government to investigate.
you can also distribute the code/content for other sellers to use so they do better than him or you may be able to get him on intellectual materials infringement. i dont mean to be particularly malicious, but you could also distribute his information and let people have at it.