Something went wrong error after upgrading

Haven't been able to log into Xfinity app since September. Ever since I upgraded my services to a higher speed I cannot log in. I have talked to about 15 Xfinity people now and done everything under the sun to try to get it to work. I need to control my children's internet, I have devices that are paused that I can't unpause. Seriously considering switching to Google fiber because nobody can fix it.