Over Promise no delivery

We went to sign up for Telkoms fantastic product that they are offering for WIFI to be installed in our home. It has now been 5 weeks and every week we get an sms to say thatt the technician will be at our place to install the wifi and we must be available from 07:30 - 16:00 during the day. We have now taken 5 full days off from work and there was a no show. Every time we call in almost twice a day all they can say is that the technician will be there before 16:00 and still there was no show. When phoning in to complain, and calling from cellplhones, spending 30 - 40 minutes on a call, they just said they will escalate it. We then asked for a manager to contact us and still to date no one has contacted us. We feel that why have such a fantastic product when you can't deliver on the service that goes with it. This is by far the worst experience in customer service that we have ever experienced.