I've sold on there over the years faultlessly...until last year. With the two items I sold the buyers wanted endless technical support, both claimed the items to be faulty. One was described as having a fault which despite eBay siding with the buyer I did eventually get reimbursed as he refused to return it. The other I had to endure about a week of explaining to someone how to setup a Cisco phone, even sending them .xml files before he gave up, claimed it was faulty and returned it, I got it working within minutes of it being returned, the guy even asked if I could provide a VAT receipt even though it was a private listing on a 2nd hand item - to coin an OcUK phrase "I AM NOT A SHOP!".
So I do have a somewhat tainted view of selling on there. My advice to the OP though is get as many pictures together as you can and have them returned, for the small amount it comes to it simply isn't worth the hassle, get together video evidence of the returned item being unboxed and if he is trying to pull a fast one report him to eBay.
The problem with eBay processing millions of transactions per day does unfortunately leave them in the position where if one seller stops selling then they know someone else will step in and take over and so it gives them little incentive to protect the seller more than they have to.
