Re-installation booked a month in advance

Have booked a Re-installation a month ago already and took a day off work for the installation I was told that the installation would take place between 12h30 & 16h00 when I phoned telkom numerous times and holding on for no less than 30min each time I got hold of an consultant and when I requested assistance as to where the technician is her answer was \she cannot help me"I then asked to speak to a manager she then said that they are not available. This is the most pathetic service I have ever received and I ask the question \""WHY AM I PAYING YOU FOR A SERVICE WHICH YOU CANNOT DELIVER???\"" This is unacceptable!!"""