Iwyze not loyal to their customers

I got into an accident July my car fell with the side and spin several times the car sides was badly damaged,Iwyze tow the car to auto tech panelbeaters where fixed they the body and few things, but they took very long because I only received the car mid November.After receiving the car it gave the check engine light I sent the email to the insurance they said according to them it's not accident related but I must take the car for diagnosis then if it's related they will pay.Before I even take the car for diagnosis it just stop on the road not moving even if I put on gears,I called the insurance they towed the car back to panelbeaters on the 23 November but since then I've been phoning them to give authorisation so the panelbeaters can attend to it I'm getting no joy out of them instead the consultant told me according to the report the engine it's not accident related. I do not know how they figured that out because the car had no problem before the accident,and after the accident there was too much smoke coming from the car bonnet and exhaust pipe and the car was not moving by itself.