Are there two "delivered" numbers? If there is only one, it would refer to the first self-delivery.
I'm willing to believe the seller, it wouldn't be the dumbest thing I've ever done. All that would be required is putting your address as the From and his as the To.
If there are two Delivered, he's either too dumb to breathe without help, or scamming.
In addition to Not Recieved disputes, there are disputes for Not As Described.
It's sketchey, but NAD would be one way of describing a purchase that was invisible and inpalpable.
Paypal also covers you but again Not Received is difficult when tracking shows delivery somewhere, and Not As Described is sketchey. Also PP demands that the buyer pays for return shipping of the NAD item.
If you paid with a credit card, or back your PP with a card rather than a balance, you can also try a chargeback.
But let's hope the seller just had a "blond moment" and your package is on its way to you.
Bekind to the handicapped. There are those who are hard of thinking.