Non delivery of paid service

On numerous occasions over the past year, I have opened tickets to get my services restored to 10MB that I pay R799 per month. While the technician is on site, the download part of the service is restored, but upload remains an issue. They were recently taken over by HeroTel, but poor service delivery seems to remain. They must have known from the start that they could not provide the service, yet they continue to sell a product that they cannot deliver. Since end of January 2017 I have paid my account in full, on time, including the installation fees which were paid before installation of their equipment. Why sell a product you cannot deliver and then knowingly charge a customer for the service they do not get.