Takelot refuses to even test water heater.

I baulght a water heater from Takealot. The device was installed in my house in my bathroom by a qualified electrician. The device needed its own breaker switch on the main electrical board because our plugs (in SA some older houses) trips the house's power. This is normal and happened to my friend as well. My friend was the reason I baught the device. It is easy and saves money. The electrician that installed my friend's device is the same one that did it in my house, and has done so in many other houses, his work is neat and clean and even though it is an extra fee that I have to cover it is still cheaper then a new smaller geiser or solar panels and the water is instantly hot. The electrician had to cut the power cord to install the device directly to the main electrical board. When we ran water through the machine, we switched it on (as per instruction booklet) the device shows the water temperature but does not heat up the water. We read throught the instruction booklet cover to cover and found nothing we could do. I asked the electrician to put back the original cord (he did so very neatly) so I can send it back. I returned the device because I wanted it fixed, I do not want a new one, just it fixed because it is probably something small inside like a sensor or something but Takelot refused to take the return further then shipping because the power cord was cut. I explained the situation and tried to e-mail many times but was simply stonewalled. I was told they would not even test it (which would prove the point that I am trying to make) because they don't do that at the centre? On the one hand I understand you have policies in place but on the other hand I have spent a lot of money at Takelot and have supported the company since it's start, why can't they at least test the device (it will take them 5min, all you need is a good power supply and water supply, the pipes are included in the package) and sort it out with the supliers? I have spent well over a 100k at Takelot but now because of this and the flatout disregard to even test a loyal customers request I will never shop there again.