Warrantee failure.

I bought an Axpert 7.2 Max inverter from DIY Geek. Full Circle Solar is their supplier and they must uphold the warrantee on this supplied product. It was faulty out of the box with the cooling fan running at an excessive speed at very low load conditions. As I have the same inverter and has installed one at another customer, I am in a perfect position to compare their performance. Three independand people observed and noticed the problem clearly. I returned the inverter to GIY Geek at my own expenses (R264.50). After more than a week I received feedback that "there is nothing wrong" with it. This clearly cannot be correct - three people cannot be wrong!! Previously ordered inverter worked 100% correct with fan speed according to load conditions. I do not know how this is going to play out but I will never do any business with DIY Geek or Full Circle Solar ever again. This is not service at any level especially if items are brand new and under warrantee.