Bad service

I took my boxer for service today, only to find out at 16:25pm that they found a problem with the car and the part can only be ordered on auth, now i run a start-up business with this car, and i have clients that i offer a service to. I took the initiative and called them 15:00pm to find out if they were done with the car, only to be told by Tania that they will call me as she had no clue what was happening with the car,an hour and half later K.Smit calls to say they need two more days to sort out my car. He did not even sound like someone who cares what happens to my business, no sense of urgency at all, now i'l be loosing clients and money to an average amount of R5000.00 for the days car is with them, this is not professional at all, why wait for till last minute to inform a client of the outcomes or even worst for the client to call you. I don't think this people take me and my business seriously. Now my business will suffer because of their incompetence. This ordeal makes me very angry as this is not the first time they treated me unpleasantly/unfairly.