Passing the buck for work not completed

I brought my car into renew-it for repairs last year December. There were 2 work orders and only one was completed. When I picked up my car I was promised that the repair would be completed in January and I will have a rental car. Since then after multiple calls and unanswered emails and being passed person to person the repair is still pending and there is no acknowledgement from Renew-it on when the car can be brought in and the remedy for such inconvenience. I would suggest that if you have another company that your insurer recommends that you take the alternative because renew-it has no intention of of fixing any problems.