The administrator has the ability to overlook the usage of the service:
Please note that if you don’t see the “Company usage” option, you have not been set up with Company administrator rights. Please contact your supplier or another other Company administrator to grant you access.
The usages statistics goes back three months and displays call minutes per day. Endpoints, Users and VMRs can be investigated separately on this page. Clicking on the different category (endpoint etc.) gives the separate overview.