ITS Heat Pumps & Solar not very helpful in solving problems

I had a solar panel installed by Carl Putzier and agent of ITS Heat PUmps & Solar, in December 2017 the Solar geyser overheat all the time, The insurance (Santam) came along and found that the solar panel was incorrectly installed, I contacted Carl which came and fixed it but it still overheat and I kept on emailing him in this regard. Eventually I contacted Stefan Bester – Head of Technical of ITS Heat Pumps & Solar and he reckon that the solar panel is way to big for one geyser Carl came up with a solution to fix it. But neither Carl or Stefan assist me in solving the problem with the solar.