I'm very sorry, but there is no loophole.
eBay have an excellent 30 day MBG, Money Back Guarantee policy so it's impossible not to receive a full refund if you didn't receive your item and the seller has no tracking to show delivery. However, you must follow those rules, and unfortunately you didn't.
Never listen to any excuses or promises a seller may make, and it is vital to keep an eye on the time, you Must open a case for item not received within 30 days of the item's last estimated date for delivery. Equally importantly you must escalate the case if you do not receive a refund within 3 days. eBay step in and force the refund.
If you forgot to escalate, the case times out and closes through inactivity.
eBay's 30 day MBG is written on every listing on the right hand side, familiarise yourself with it, it could save you a lot of money in the future.
Here i is:
https://pages.ebay.co.uk/ebay-money-back-guarantee/
You cannot open another case for this item with eBay, but you can turn to your payment provide for help with your refund.
@rajarahman2016