I had this happen to me back in June. I was furious because this guy left me a neg then did the chargeback thing and something about the way the guy was conducting himself led me to believe he had in fact received the dvd. I looked up his address again, and luckily he lived in a fairly small city (not NYC or Chicago sized) and I then checked the internet for the chamber of commerce information and found out through 411 the address & number of his local district attorney's office, local police dept. and found out the name of his local Post Master with the USPS.
I had to refund his money with Paypal as it didn't want to get the extra charge with Paypal if you don't voluntarily refund and I then emailed him and I told him I had spoken to his local USPS (and I provided the address and phone # to add credibility to my story) and that they were looking into the possibility of fraud, and I told him I was awaiting their response and was proceeding with contacting the DA's office to press fraud charges, as well as the police dept. Again, I included the address's etc. I think something about them recognizing certain address's and area codes that leads them to believe you're serious.
Anyhow, miraculously, it seemed that he did in fact receive the dvd after he received my email. Took me a few more days but he finally refunded my money via Paypal. Sadly I was stuck with the neg from this pond scum, but I got him back anyway. He was a zero feedback. I decided to not immediately leave him a neg as he'd just start over with a new id. I kept my eye on his id for a couple of months. Sure enough he did a couple of sales and he received a few positives. I then went in for the kill and left him a neg. Boy, was he angry. He emailed me a real nasty note telling me I was messing with the wrong person and he was going to get back at me.
I didn't appreciate his threat so I dug a little deeper and I noticed that there was some obvious shill bidding going on between him and his few sales and feedbacks so I reported him to ebay for shill bidding. Although they (ebay) don't confirm anything to the "reporter" within a day or so, both id's were naruu'd so I did finally get some satisfaction. If I were you I'd try bluffing this guy that you are going to file fraud charges. It does tend to scare people if they are indeed trying to pull a fast one. GOOD LUCK!!!