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

Note: This comment was created from a merged conversation originally titled Where to file a complaint about bait-and-switch tactics?

user_whe8m1, hello there and thanks for reaching out. I completely understand your frustration. I want to thank you for your tenure in this time as well. Let me see what transpired on your account so I can help assist with getting this matter resolved. To move forward with your concern, please send us a direct message with your full name and complete service address. From there I can authenticate your account and assist you further.  

To send a direct message, please click on the chat icon in the top-right corner of the screen, and select "Xfinity Support" to initiate a live chat. 
Click "Sign In" if necessary
Click the "direct messaging" icon
Click the "New message" (pencil and paper) icon
Type "Xfinity Support" in the "To:" line and select "Xfinity Support" from the drop-down list which appears. The "Xfinity Support" graphic replaces the "To:" line
Type your message in the text area near the bottom of the window
Press Enter to send it.