Was it on another account that you sold the item? I can't see any sold listings, just your active one.

Can I ask what the item was? Unfortunately, eBay is geared towards the buyer. If you escalate the dispute, or ignore it, eBay will close it in favour of the buyer and refund them from your PayPal without them having to return it. If you ignore it, eBay will kindly issue you with a defect. If you have only sold a few things, it could be enough to drop you to below standard.

I can only suggest that you tell the buyer that you will accept return of the item, which you will then refund after it has arrived. Sadly, it's really your only choice. Anything other than this you will lose both the item and the money. 

It doesn't matter how many photos you upload, eBay will still side with the buyer as most of the dispute process is bot generated. You could try calling eBay, or use the call me back option, but I still think that would fall on deaf ears. Certainly worth a try though. Click on help at the top or bottom of any page. Select any option that shows, and scroll to the bottom to the call us / call me back option.

Edit: too slow! Hi Lyndal 😄