In competency can lead to major damage do not use them!

I have excepted their quotation of over R10000 to install 3 x extra solar panels to my exciting system and after they did the installation nothing worked: 1. The new panel was put on an angle and the first night almost blow off due to wind. 2, Later that afternoon I call them back as my system was not working- request to uncouple the new installation to proof that my old system is working. 3. Now I was very worried as they start to Google and tell me they know what is wrong and will come back the Tuesday to fix it. 4. The Friday they arrive, and rework started on the following: Solars was put onto the roof in line with my first Solar panels (I supply the brackets) New power line was installed from the connection that was only done in my roof to my old system (wires connected like *********** people into my wires with no additional protection) They install then similar to my old system the switches and re-route the wires and when startup the system it did work for 10min and switch off again due to faults and I am very lucky that my inverter was not damage. I call another contractor and he told me to switch the new added system off and that he will not issue me a CoC for the work done. His words where it was the worse installation he saw based on the following: Earthing was not done. Panel shock you when touch. Wires routed through tiles/no conduit for wire lay open on ceiling. Trip protection was not installed. They install an "auto trip over switch" if I need to use Litium batteries later they told me, but those are only use if you have a generator as per the other contractor?? Then on top of not been able to handover a workable system they charge me with a new invoice of almost R4000 again which I refuse to pay. I then ask them for a CoC, and they could not provide it, in order not to burn my house down, I switch the power off and request them to come and remove their system and payback my money. They confirm feedback to me the next day but never contacted me and I had to get another contractor to redo everything. My final view is they work on trial and error and not competence in this field at all.