The number of users on the system has exceeded the limit

I am getting below error message

This is an automated notification from ZeXtras Suite.
The following warning(s) have been detected.

The number of users on the system has exceeded the limit allowed by your license.
Because of this, all the ZeXtras Suite paid modules will be forcibly disabled.
The ZeXtras Chat and any other free feature won't be affected.
We suggest to delete some unneeded users or contact your local reseller.

See below for extended information.

Number of Users on the system: 2142
Number of Users allowed by your license: 10.

My requirement is i dont want to enable the Mobile sync all the user so who ever required will enable the enable it and purchase required no's

please advise

Thanks
Manickam