Refund my money from Scam seller. With strong evidences how can this end in seller favor?

[Kay1957]

So after seen all these evidences as follow could you please tell me. How can the case close in Seller with the reason that Paypal have not received valid proof that the merchandise was returned. when I did everything that Paypal  asked of me.Try to get a Refund back from scam seller, but it's end in Seller favor,  the reason given for this decision is that Paypal have not received valid proof that the merchandise was returned (a full refund having been previously agreed by the seller if the merchandise was returned).  which is NOT CORRECT I have previously provide the track able number I receive from royal mail as paypal requested, I even send paypal the Certify proof of postage stamp by Royal mail.  in fact provided the proof of despatch - however it may be that due to the protracted nature of this case your reviewer failed to open the correct link?  http://parcelsapp.com/en/tracking/RY073668060GB  

  
Accordingly I am again enclosing all the relevant images and links that confirm proof of postage and show the goods being in transit (as of today the latest shipping information shows the goods being in China, it's has been clear by the custom and still in transit but not yet received by the seller)

The following image also show the evidence that Paypal has contacted me confirm "Return the item (s) to receive your refund * please note that I have received 1 item so I return 1.. also previous evedent comfirm by the seller that he only send 1 item. then paypal also send another confirmation that Paypal received the "tracking information which is now been send to the seller"

Could Paypal please supply me with the reason why the seller did not give me the refund for the item that they didn't send. As I previously mentioned, I ordered and paid the seller for 2 items on 26th February 2020, however only 1 item was delivered on 20th April (manufactured with wrong measurements). After I waited over 2 months, I try to emails them but no respond and realize I was scam. NB - the seller only shipped this item after I had filed the Paypal dispute! The seller said He would give a full refund if I returned the purchase to him at my own expense, WHICH I DID.  

This is the email evidence that the seller sent to me... in which they had admitted that the item that I didn't receive was out of stock.
 ................

"Considering lack of manufacturing due to Covid-19, we have no choice but canceled the item which is out of stock and shipped what is ready. We are so sorry for the inconvenience that suit did not fit you.  Will it be possible to give others as a gift? Or how about we make you a partial refund as a way to make up for this?"

Now It's end in this scammer favor I follow paypal link and cannot find appeal the outcome.. so someone please help.

Images of packed goods. 

Image of shipping paperwork with Royal Mail Stamp mark and official proof of postage

Link to relevant Royal Mail Tracking page

https://www3.royalmail.com/track-your-item#/tracking-results/RY073668060GB

Images of the package Tractable linked from China Post page (Royal mail partner website) and from royal mail Tracking website

http://parcelsapp.com/en/tracking/RY073668060GB       

Did more research appeal that i'm not their only victims.