Unhelpful Customer Service

I am nearing the end of my 2 year promotional rate on my current internet service. About a year in, I contacted customer service and was told when my promotional rate expires, I can contact customer support shortly before that and get it extended. I saved that chat transcript as proof of that interaction. So just now, toward the end of my promotional rate, I spent ages chatting with customer support who first said they could help do exactly that and extend the rate, then when I declined the upgrade internet speed offers, I was then told they couldn't help me keep my current rate. When I asked what had changed in those few minutes and why I had previously been falsely told that I would be able to keep my current rate, the agent replied "sorry" and disconnected from the chat. This is extremely unhelpful, rude, and a massive waste of my time since it took so long to get to a point where the agent just disappeared and disconnected. 

I find it incredibly frustrating that Xfinity is willing to lie to customers to keep them paying, and then be as unhelpful as possible in following through on their promises.

I have saved the chat transcript of all these encounters as proof of this horrible behavior.