eBay Unfair Business Practice: Fobbing off a genuine complaint

I am an experienced e-shopper and have never had a problem with any organisation I have used, until my first experience of e-Bay. Based in South Africa, I bought a Wonder Woman poster for a birthday present for my granddaughter in Andover, Hampshire. On eBay, This cost £ 20 and everything went as normal, until I received an eBay notice that the parcel had been delivered. My son, however, told me that the parcel had not been delivered. He works from home, and there is always a family member at home, available to accept mail order parcels. I queried the problem with eBay, and they told me that as far as they were concerned I had no claim. They gave no reason, and closed the query. Essentially, I was fobbed off, and eBay has no mechanism to launch an appeal. So I have lost £ 20 because I used eBay, and looking at the reviews, I see many, many people have had a similar problem with eBay. I ordered the same poster from Amazon as a replacement, and it was delivered four days after my order was placed. Based on my experience I will never again use eBay, and I am going to take the matter up with the UK consumer council (https://www.consumercouncil.org.uk/). Use eBay at your peril, good reader!