Problem with eBay purchase

[Foxy_noms]

I recently ordered bought an item on eBay of which the seller contracted city link to deliver the item.

I was at home on the days of estimated delivery but unfortunately city link failed to deliver the item on both those days. Although they say they attempted delivery on one of those days. I had contacted the seller on the first day of estimated delivery to find out if there was a tracking number for the item so I could do a follow up, but the seller never responded. I went on holiday thereafter.

Fast forward 1.5 weeks, I got home from holiday one evening to find the package left at my door, damaged. I did not sign for it, city link just left it at my door.

At this point I requested a refund from the seller and the seller told me to return the package. I arranged a return with city link, who had initially refused to come and pick it up. I have all of this in writing in an email trail.

Fast forward a two weeks, I still hadn't heard from seller with my refund so I logged a case with eBay. eBay decided in favour of the seller because the seller apparently has not received the package.

I contacted city link who have plainly told me that they have no case to answer because they returned the package to seller.

Someone is being dishonest here and I'm not quite clear who it is. I want to start a case with the small claims court but I need to know what's happened to the package.

What would be the best way for me to proceed. Please help.

Would it be better to start with the police to try and track where the package is?