If you are trying to add your bank details to your eBay account do so here:
https://ppcapp.ebay.co.uk/myppc/wallet/list
If you are trying to register for eBay's Managed Payments, mandatory if you wish to use your account for selling this link explains the process:
https://www.ebay.co.uk/help/help/selling/getting-paid/introducing-managed-payments-ebay?id=4795
If there is still an issue with any of the above access to your account is needed and for this you need to contact eBay Customer Services, they can see where the issue lies and explain the steps you now need to take.
Contact them this way.
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.
I recommend contacting CS first thing in the morning as there's more chance of Dublin answering.
@st-28451