Remove unauthorized users from access to streaming my account

please deprovision all users on my account.    I have tried to remove devices that were previously remotely logged onto my account to use and they never signed out.  I would like their access to log into Xfinity hotspots and Xfinity Stream using my acccount removed.  I have deleted secondary user names and changed my password many times and they still remain able to access my account. Please advise. Thanks for any help.