In 2005, I payed a man 30,000 dollars for 100 X Box 360 video game consoles. He refunded 11,000 and never delivered the product.

The short answer is that you need to file a summons and complaint in District Court. Of course, the form of the complaint, the elements to allege, the discovery process that will follow, etc. can be difficult to navigate. Add in that you will have to do this from New York, and you would likely find hiring an attorney to be well worth the investment.

The clerk's office my have some helpful advice if you do insist on going it alone. Good Luck.