Can you call up your (father's?) provider and report the phone stolen? Aren't those IMEI's blacklisted? If so, that might make it difficult for the buyer to unload. I guess you could also threaten to do that to said buyer, first, to see if that provokes anything.
Either way, a bummer of a story. I've had my own issues with eBay and rarely check there except for infrequently needed (cheap) odds and ends. I hope it works out.
