I have sold my old iPhone 3GS on eBay. The buyer received it yesterday, but however I received a call from him saying the iphone box was there but no iPhone was in it.. I already contacted UPS and there investigating it. Now I have the IMEI number and Serial Number for that phone. I just contacted ATT and they said there is no way to track it even with that, is that true? There's not even a way to see if it's activated??