You are not talking to eBay here, we are members just like yourself.
Some sellers do give excuses and promises to make a buyer go over the 30 day time limit to make a claim. Never listen to them you just needed to open a case for item not received, within 30 days of your item's last estimated date for delivery to receive a full refund.
As this timeframe has lapsed, you'll need to turn to your payment provider now, for help with a refund.
Familiarise yourself with the link below describing eBay's 30 day MBG , Money Back Guarantee policy, it could save you a lot of money in the future.
https://pages.ebay.co.uk/ebay-money-back-guarantee/
@auredzid0