How do I get Cox to understand my issue and get it fixed?

How do I get Cox to understand my issue and get it fixed?  I spent over 3 hours (over 2 days) with the "Help" guys, and the problem still isn't fixed.  I did everything the help guys had me do. I even went to the Cox store and got all new modems and cables.  There isn't much more I can do at my end.  I firmly believe the issue is at Cox's end.  What's the problem?  All of a sudden, the audio freezes but the video keeps going, or maybe only the video drops out but the audio keeps going, or maybe both will drop out.  I was online with a tech for 3 hours (over 2 days) and we both agreed the problem was at Cox.  And the last guy said it would be fixed by March 30.  Guess what?  It's still a problem.  So is there a way to get to some big shot at Cox who knows what to do or who to speak to in order to get this fixed?