You do need to persist and contact eBay Customer Services again, as only they, can tell you what else is needed for your selling account set up with eBay.
I do recommend, contacting CS, only very first thing in the morning when the lines first open at 8 a.m. on weekdays, and 9 a.m. on weekends, as there's more chance of Dublin answering.
There is no phone number for eBay , it's a Call Back option.
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.
@saud12345