I made no such statement. I will not confirm if I have a heat pump or not, as my ownership status of such a device is irrelevant to this thread.Thank you for at long last admitting that you have no experience of using a heat pump in domestic environment.
I did not suggest the the manufacturer does not know their own equipment. I'm sure they do know it very well.It does seem that according to your post the manufacturer does not have a clue about installing its own products?
What is clear, assuming your reports are accurate and fair, is that the system you have is not performing as you would have hoped. I suggested some of the most likely reasons for your dissatisfaction with the operation.