Slow to No Feedback from about the rework on my car!

I was in a car accident in September 2017 and my insurance took my car to renew-it but they did such a bad job which i reported to renew-it and my insurance., it has been 5 months since i got the car back and all the complaints submitted but still the car hasn't been fixed properly! The panel beater doesn't take me seriously as they make promises and not keep! My insurance promises to follow up and get back to me to ensure this sorted but they don't! what the hell do i do now! the value of my car has dropped, it is way more damaged than it initially was! Where do i report this **** now?!!!