How to remotely log out all users?

Short version: someone gained access to my account. I changed the email address, phone number, and password on my account. Then I changed the wifi ssid and password.

However, on my old phone I was still logged into the app using my old login information, and was still able to view the new ssid and password... plus all my new personal info :/

I want to make sure all users are logged out but I contacted support via direct messaging who informed me that this is only possible with Xfinity Stream, not the Xfinity app. How can I secure my account against this continued unauthorized access?