Miserable customer service from Cox

This is truly disappointing. I was installing a new Panorama wifi at my daughters apartment. When it didnt work I called tech support and after 20 minutes spoke to someone who couldnt help but made a service appointment. She warned me I could be charged $100.00.  A few minutes after hanging up I fixed the problem myself. I went to the cox web site and it said I had no upcoming service appointments but just to be sure  later that day called Cox to cancel the appointment. After waiting half an hour the agent came on line and she said it was canceled. Yet I never received any cancellation notice. Today I received a reminder that the technician would arrive. I clicked on the button to reschedule and it took me to a page that said I had no appointments. I called tech support, waited half an hour and again she said it had been canceled. I asked to speak to a supervisor and was on terminal hold. I gave up.

How can a high-tech computer company 1) not send a cancellation notice, (2) keep sending reminders when there are no appointments?  This is really awful

Ram