You can either contact your local authority library to report the problem, and they will be able to notify you of the issue / unlock your account. If you are unsure of the contact details of the library, please go to ‘Find My Nearest Library’ on the https://libraries.wales website (front page under ‘Join Your Library’), where you will find the details,
OR you can send a message using the Enquiry service, quoting the issue and which library authority you are a member of.