"No input" going to TV

To Xfinity Support:  I would like to obtain help from a live person by phone.  My 4K cable box is not communicating with my Sony TV.  I get the error message "no input."  I have unplugged and replugged the cable box and the connection to the TV.  Earlier this week I also had problems with the cable box not communicating with the TV, and at that time your system allowed me to speak to an Xfinity representative, who supposedly "fixed" the then-problem.  Now this occurred.  I need help.  Your system currently won't connect me to a live person, and just sends me in bot circles that are not helpful.   Please connect me with a live person or a supervisor.  If this is a posting vs a message to xfinity, I'd appreciate any tips on how to communicate with a live person.  I've already tried the phone and xfinity/support/schedule-callback (which refuses to let me schedule a callback).  Thank you.