Xfinity not honoring promised grandfathered plan and lying employees

I have been with Xfinity for 10+ years and recently moved home. I was paying way too much for my plan with yearly increases. When moving home my partner looked into joining as a new customer and also alternatively getting Verizon. Both options were significantly cheaper. I phoned up Xfinity and was told by the representative, that they could honor my existing grandfathered plan and a much lower rate, and provide faster internet and we could just plug all the existing equipment in without the need for any installation. Unfortunately, we realized this was not the case. Nothin worked and Xfinity told us we required a technician to come and install everything at a $100 cost to us. After everything was installed, our premium channels which we used to get stopped working. When phoning Xfinity up, we were told that the prior representative who promised us our existing plan lied to us and deleted the old plan and they couldn't reinstate the old package and told us we would need to pay an astronomical amount to get everything we used to get. Over the last month we have spoken to a dozen people, each saying something different, promising to make it right and guaranteeing callbacks from supervisors who would rectify the situation using back channels. Of course, none of this has happened, nobody seems to be willing to make things right and we have wasted many hours on the phone, and meanwhile we are getting billed for a subpar service we never agreed to pay for. I. have honestly never encountered such terrible customer service or lack of accountability. At this point I am seriously considering cancelling everything and signing up with Verizon, for faster internet, more channels and a locked in price for 4 years. Why is nobody vested in customer satisfaction at Xfinity?