Nominet, the .UK registry, has a Data Quality Policy for all .co.uk and .uk domains. They require that all changes to personal information on registered domains are validated through this process. This is something that is out of Yola's control. For more details, please read the Data Validation article.
As a result, your domain may have been suspended in accordance with their policies. For information on how to address this, please visit Data Quality Verification for .UK Domains.