Suntank Solars' pathetic products and service.

I had a new 200 litre Suntank solar geyser installed on 18/11/2019 and on 4/1/2020 the electrical earth leakage of my house started tripping the moment the thermostat swithed on to heat the water in the morning. A certified electrician confirmed that the thermostat is faulty and is responsible for the tripping of the earth leakage. Suntank refuses to supply a new thermostat because they did not do the installation - despite the fact that they do not have a branch in Cape Town where I live. The thermosta is only six weeks old but they hide behind a so called "factory warrenty" and that it is not their problem. I have spend R14 000 with them in the last months to replace two solar panels, which burst, and the new geyser. They are totally unhelpfull, do not phone back and one is not allowed to talk to any senior manager and the person who answers the phone just hides behind the fact that she cannot help and have to ask a senior person. How unprofessional can a company get - I curse the day that Suntank products were installed in my house. How can a company keep on doing business in such a poor and unprofessional way?