My thermostat is not showing in my Alarm.com app
It looks like you are using the Alarm plan, that plan does not support thermostats and other automation device control through the app.
The Home plan supports thermostats. I see it looks like you tried to switch to the Home plan but there was an error. Please try your service plan adjustments again now in the system manager. If you continue to have issues you may need to ok the purchase with your bank.