Suggestion for the future. Contact the seller for help before opening a case against them. Sometimes items are delayed for reasons beyond the control of the seller - yet by opening a case, you have automatically given the seller a bad mark on their selling record. Since a seller can only receive one bad mark per transaction, they now have no reason to even try to help you - they simply need to prove to eBay that the item was delivered and they are in the clear and you are out of luck.
It's always possible that it was delivered to the wrong address. It happens all the time.
You may not have been scammed - he could well have sent it and honestly believes it has been delivered. Ask the seller to contact the courier company on your behalf (they won't deal with you direct - their contract is with the sender).
Contact ebay asap and tell them you didn't sign for anything and never received a package.
You could call an investigator or the police, or report him. Get some sort of authority to help investigate, or call the people who work at ebay.
I bought a brand new ipad air from a seller in ebay. he said It will take 5-7 days to deliver but it didn't arrive. so, the next thing i did was to open a undelivered item.
He said he delivered it and has a tracking too. but 15 days from purchase , it still hasn't arrived. Ebay seems to support him because he has the tracking and it says arrived and it says delivered on the verified address.
i was home all the time.
I spent 400 pounds on it !.
it was a gift :( help