You are a new seller and it looks like eBay wish to verify some details on your account, or something missing from registering for eBay's Managed Payments.
You are given clear instructions to contact Customer Services, have you done this?
I recommend contacting CS first thing in the morning when the lines first open at 8 a.m. for 'live agents' as there's more chance of Dublin 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 for ' live agents' 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.
I recommend contacting CS first thing in the morning as there's more chance of Dublin answering.
@happystore147