Don't waste time talking to some underpaid clerk.
Go to the Resolution Centre at the bottom of this page.
Open an Item Not Received Dispute.
The first suggestion is to contact the seller. You can't so skip this suggestion and go directly to a Claim.
In the text box say that the seller is Not A Registered User. (NARU)
This usually speeds up a Claim.
The robots will ask the seller for proof of delivery (delivery not shipping). When he does not provide that , you will be refunded.
While millions of transactions go smoothly every day, there are statistically going to be thousands of problems. Telephone handling of those problems will not work.
Your problem is simple and straightforward so allow the robot system to do its work.