I'll bet you got the "invalid number" message because the fuckwad isn't a registered ebay member anymore.
yep, you're right!
Again I recommend that you go through Paypal, not Ebay. You may still have time to file a claim, but get on it ASAP. I filed AFTER he was no longer an Ebay member, and I still got my money back. The whole transaction details are still in my Paypal account details, so you should be able to file a claim if you are within Paypal's time limit.
Oh, someone else must have given him a negative, as his rating is down to 85%.