Windows Service not stopping, stuck at unsubscribing ews subscription

The service acts like a mail watcher on a mail box and is working fine after installing on a new server. But, while stopping it, i get this error message that the

the service cannot accept control messages at this time

and all the ways to kill it didn't work. It gets stuck at removeSubscription() as per the logs.

public static void Unsubscribe ()
{
     if (_ss.Id.Length>0){
              Logger.log("Reached Here");
             _connection.RemoveSubscription(_ss);
       }
}

Here _ss is the streamingSubscription, _connection is streamingSubscriptionConnection references

Can you tell me how to fix it? P.S.: the same service works well on other server.