Microsoft Lync Account – Domain error while removing

Hello,
I have a domain name with my Microsoft Office and want to move from one account to another. When I click on “delete” the error message shows somewhat it is allotted to this domain even there is nothing in this domain. Would you please help me to find the possible solutions?
Thanks.

Unable to remove domain
We cannot remove the stevebates.co.uk domain because of one
or more of the following issues:
· There are user accounts associated with this domain.
· There are email or Microsoft Lync accounts using this domain.
