File a complaint against Xfinity

I have an expensive plan, which includes Voice, Cable Internet, & TV.  My bill is significant, and has been for decades – I am a long-time customer and I don’t get treated as such. We also have Xfinity Mobile. The experience I have had with Xfinity - Comcast Voice is completely unacceptable. The voice mail system is intolerable, so I asked to forward my calls when there is no answer.

Background: This a highly basic feature. But Xfinity only provides the setting to select for

1. Forward all calls (it never rings - goes straight to the forwarding line) or
2. Selective forwarding - only forward calls from certain people. 

What I want is simple, let the phone ring a few times and if nobody answers forward the number to the forwarding number.  I can't understand for the life of me, why this would not be automatically offered -- it is SOOOOOO basic! The is the whole point of forwarding, to send the call elsewhere if you can't answer.  

Experience:  I have contacted Xfinity at least 6 different times on this topic and get this to work. I have always been told it can be done, but it never gets done.  I was first given 2 different set of instructions on how to activate "call forwarding no answer" from my home phone - those do not work. The feature is not somehow ‘automatically’ available for my line. Then another super long chat and a ticket was opened and a call back was promised, but no call back.  Then another tech on yet another long chat promised to have added the feature while in the chat and that it would work in an hour -- nope it didn't work.  Then another call with yet another chat tech, who promised to have it taken care of and that I would get a call from tech support -- a call comes through, about an hour later, as if it was not schedule because it then told me I have to wait 40 mins for customer service rep. What? Are you kidding?  I need to give you endless hours of my time to get you to do your job?  This is 100% ridiculous. Promises, promises, and nobody does what they say they are going to get done. Hours on chat or the phone, and I still don't have my hyper basic feature, that should just be available form the Voicemail settings via the website.

I need this elevated to customer service complaints, because this service is extraordinarily poor and inexcusable. My time has been wasted and I have been routinely lied to -- told something is certainly fixed when it is not. Fix this!