Where to file a complaint about bait-and-switch tactics by Xfinity?

I am having the same issue only with the price quoted for a new phone. I have the entire chat in writing and have so far been shuffled through 8 individuals. I asked 3 times what the final price for the phone would be with the same answer each time. I have 2 payments left but Xfinity wants me to pay full price. I am so disgusted with this illegal bait and switch tactic. I told the chat representative Xfinity needed to own their mistake and got a sorry can't do anything response.  I am not backing down on this. I plan to contact the state attorney general, the FCC, the Better Business Bureau, the reporters who go after crooks for the public, and anyone else I can find. I am fed up.

Hey there, @winger1960, thanks for reaching out through Xfinity Forums. We would be happy to take a look at your Xfinity Mobile billing concerns. We want to ensure you are being billed correctly. Please send us a Direct Message with your full name and your full address.

@winger1960​ I suspect their support department is off-shored and largely disconnected from the executives of Xfinity.  The fact that the customer support engagement team cannot escalate to anyone at corporate is a huge red flag.  That level of isolation is either executive-level mismanagement or intentional so they can maintain plausable deniability.  

@XfinityQue​ Sent a direct message.  

Thanks for any assistance.

After directly messaging with the Xfinity Support representative in the forums, it is clear that Xfinity will not honor the offer they made (I have documentation).  I am okay in being pushed to leave Xfinity and become an AT&T customer from now on.  I will make it a point to share my experience with my friends, family, and followers.  I will do my part in reporting the unethical business practices and showcase how I have made every attempt to enable Xfinity to fulfill their commitments, but Xfinity made the choice to not honor their offer to a longstanding customer.

If this is how a 'valued Diamond customer' of 13 years is treated, I no longer want to be a customer. 

We can get it to the proper internal team to handle your concern. I just needed some additional information, do you remember the date and the name of the agent that you spoke to and did you keep any screenshots?

@XfinityCarolyn​ Yes, I downloaded the Live Chat conversation and took a screenshot (good thing too, as the provided transcript from Xfinity omits the customers messages).  Here are a list of names of the people I have thus far had to deal with (as in repeat the situation, listen to them trying to convince me to a new 'best offer', and then listen to their excuses to why Xfinity will not honor their original offer - that is given to new customers).

1. Prathna - Live Chat - original offer was presented and accepted.
2. Mohd - Live Chat
3. Mehul – via phone
4. Anjum - Live Chat
5. Rayadurgam - Live Chat
6. <transferred to a Spanish speaker> – account closure, phone
7. Emm – account closure, phone
8. Xfinity Support on Forums.xfinity.com

It was yesterday, Feb 17th. 

From the transcript:

Agent (02:37 pm): Hi MATTHEW, thank you for contacting Xfinity. My name is Prathna. I see you may have questions about your bill. Is that correct?

nullAgent (02:38 pm): I can understand. I will go ahead and check the details and will help you with this.