Do a chargeback via your bank with the paperwork you have, its a pretty easy win especially if it hasnt been delivered too.
With regards to ebay they will have a prepared statement ready for this something like the below;
We are eBay are very sorry to hear that a faulty item has been sold on our site, this saddens us as we take trust in our sellers. Unfortunately as eBay never get to inspect the item we can only go off what the seller has told us and in our T&C's we do say you can not sell items that are not safety tested and authentic. Our aim is to improve the site every year with increased checks but as we are just a platform to put buyers and sellers together sadly some items slip through the net. We are glad that this item did get stopped before the customer received it and we will be working to try and stop any future incidents like this.
Its the same when they have clear fakes being sold, they back away and highlight they are not selling anything just giving a space for sellers to advertise. Realistically the government need to come down harder to make eBay liable for selling fake items/business not complying with the law but until that changes eBay wont.
Get onto your bank for your funds back though, with that evidence you should win the chargeback pretty easily, or paypal if you paid via them.