eBay probably need more verification from you that you are the account holder.
Contact them, answer some security questions correctly, and that should unlock your account for use.
Use this link to contact eBay Customer Services.
https://ocsnext.ebay.co.uk/ocs/cusr?query=1455
Scroll to the very bottom of the page and you will see the options, Have Us Call you and Chat With Us, and an approximate waiting time, it's usually a few minutes.
Lines open between 8 a.m. and 10 p.m. today.
