How is this possible????
Because you don't appear to have read or followed the rules.
Providing photos of postal receipts means nothing. For seller protection against false "item not received" claims, eBay now requires the seller to upload the tracking or delivery number (on the recept) when marking the item as dispatched. Or, at the latest, before the latest estimated delivery date.
If you do this, and the online tracking record confirms that the item was delivered, eBay will not require you to refund the buyer.
If you didn't comply with this requirement, or the tracking number doesn't confirm delivery to the buyer's address, you will have been required to refund them.
