Do you have tracking to show delivery? Then, contact eBay Customer Services with this information.
I strongly suggest only speaking to Dublin who usually answer first thing when the lines open for agents at 9 a.m. on weekends and 8 a.m. on weekdays. Only speak to them, you'll hear their dulcet tone to know if it's the Emerald Isles answering.
This is the easiest and quickest way to contact eBay Customer Services, for a Call Back option.
https://www.ebay.co.uk/help/eua?id=5275&mkevt=1&mkpid
Lines open 8 a.m. - 10 p.m. on weekdays
9 a.m. - 6 p.m. on weekends.
Automated agents will be available on chat outside of the above hours.
As said, I do recommend contacting CS very first thing in the morning, when the lines first open, as there's more chance of Dublin answering.
@evenbiggerwinkie