Your items show postage with Ebay Simple Delivery.
If you used the Simple Delivery label and your buyer opened a claim for 'item not received' then Ebay would refund the buyer but you would get to keep the buyer's payment.
Which item was it?
Did you use the Simple Delivery label paid for by the buyer and supplied by Ebay?
And, are you aware you should be registered as a business seller?
Do I need a business account?
If you plan to sell casually, such as selling items you no longer want, a private account is the best option.
If you want to sell large quantities, if you have items that you've made or bought to resell or if you already have a business outside of eBay, you’ll need to register a business account.
You can't sell dozens of brand new items from a private account.
https://www.ebay.co.uk/sellercentre/selling/create-ebay-business-account
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)
