Stay away from this solar supplier

I have been struggling since the beginning of April to get a solar backup system installed by this company. 1st issue was when he tried to convince me that a 5KVA battery was a 10KVA battery, but I caught him out on that and he did then provide me with the 2 x 5KVA batteries I had paid for. Then, once I eventually got them to come and connect the system (after MANY missed appointments), the system was not connected properly, and the 7.36KW system that I paid for would not generate more than 2.5KW. He tied to convince me that the reason for this is that panels are only 20% effective. When I called him out on this (because the rating on panels is after the effectiveness has been taken into account) he told me that he did in fact put in smaller panels, but more than I had paid for. I paid for 16 x 460W panels, he installed 16 x 350W panels (he sent me the spec for the 350W panels) I then asked when I could expect the other 5 panels to make up the shortfall to be installed, and he then tried to convince me that he installed 410W panels, so there were only 2 short and he would credit me for the difference. The panels are 350W not 410W as he is claiming. He has subsequently made numerous appointments to come and check the panels and reconfigure them for optimal performance, but has never honored the appointments