Firstly, eBay do not accept photos and witnesses at the post office as proof of anything

Secondly, rather than 'request a return' you needed to open and follow through with an item not as described dispute 

Buyers can only be given positive feedback so that does not come into it either 

eBay rarely read the member to member forum, you can use eBay Help at the top of every page to contact them and try your luck

You can make sure you get a refund in future by opening the correct dispute

What is the item number?

What is the seller's feedback like?

Is the seller in the USA?