eBay's MBG policy, their Money Back Guarantee policy is written on every listing, and the basics are.... you have to put in a clam for an item received that is not working / item not as described, within 30 days of the item's last estimated date for delivery.
With excuses and promises you should not have listened to, you have gone over this period to claim with eBay.
Turn now to your payment provider for help with your refun.
Read eBay's 30 day MBG from the link below, it can save you a lot of time and money if you want to buy on eBay.
https://pages.ebay.co.uk/ebay-money-back-guarantee/
@skul2855