Zero customer service. Concern about quality of work being done.

I took my vehicle in on 08 December, was promised 3 working days. It is a month later and I still have no idea when I will get my car back and why it is taking so long. Calls are not returned, explanations are unacceptable. I am deeply disappointed and terribly concerned about the quality of work being done. Please, some feedback and finalisation on this matter is in order!