incorrect installation no attempt to rectify

I had arranged through Solar Centric to have a solar geyser installed at my house. upon completion of the work I have had endless problems with the system that does not supply hot water be means of solar power, and is totally reliant on electrical supply to heat the water. I have made endless calls and requests to Solarcentric to send out a technician to review the installation, as my electrical consumption has in fact increased instead of decreased. the installation was done in Feb 2015, and it is now August with absolutely no response or feedback from Solarcentric. This must be one of the worst case contractors I have ever come across in the service industry, and will strongly advise anyone to not consider making use of their service. I have umptious emails on record to prove my case to anyone. The problem is that not even the owner or management is doing anything about this. I need to refer this to ESKOM as well, as they should not be registered as an approved service provider. The total bill for the installation came to just over R18000.00. I still owe R9000.00 which I am not paying as the installation is not correct, and I have been unable to get meaningful response. or action