Listen this is what i want you to do .
Scenario 1
If you charged customs that means the phone should have reached india at all means. Then the responsibilities lies with PPO and Bluedart
If PPO confirms that they have shipped it , then you have to get hold of bluedart and confront them (Dont let go them easily sit in their office for hours and create scene)
Scenario 2
File a dispute on ebay saying that the packet received was empty and no phone inside it ( No matter how reputed the seller is sometimes they cheat too) if you lucky you might get your amount back
Scenario 3
Forget about everything and move on ... ( Dont doooooooooo this )
Checked the IMEI , the phone is still locked and not in use. in this situation it would be hard to find