Its a scam! I had the exact response two weeks ago. Exact. The next step is they will accuse YOU of scamming them. When they said they were going to report me it threw me off my game. Then I got pissed. I told them to go to hell.
Once they get the item (pin) they file a claim saying they never received it. Paypal almost always sides with the buyer. It sucks but the scammers found a good loop hole. Its tempting when someone offers you what your asking, beware.