Horrible Service

my wife took my car for service today at Constantia mercedes,when she got there Nichelle told me that the car won't be serviced without being diagnosed, that's **** where on earth you go to the doctor with headache then the doctor treats you for Asthma that's just an EG, from when a car gets to be diagnosed before being serviced?when she booked the car she was told to bring it at 7:30 today which she did that, now Nichelle calls her at 15H30 telling her the car won't be ready for collection what the hell is that what was the reason for her to bring the car there at 7h30 and why didnt she communicate with her earlier ,now my wife is stuck at work she can't go home office is locked she sitting outside and it's raining now how is she going to get home n to work tomorrow,i feel that Michelle offered my wife a very bad service whereby i also tried calling her at 9h00 this morning Nomsa told me that Nichelle will call me back till now i am still waiting for her call,the least she could have done was to communicate with my wife early if she saw that the car won't be ready and she could have asked to bring back the car tomorrow,at least maybe cover her petrol for about R400 just to apologize unlike telling her at 15h30 that car won't be ready how is she going to make means of transport?to me it seems like she doesnt care and it's not her business how she feels and again telling my wife that the car won't be touched before diagnosis and she must pay it in cash i feel thats ***** because the car is not there for other faults but service,i will highly appreciate your response on this and i don't want to hear things like i am sorry i am sorry because Michelle is not sorry but doesn't care,if she cared she could have communicated on time,i tried to be so nice to talk to the manager Dave which he didnt do nothing and i also spoke to the customer service Mercedes Benz SA also did nothing,Mercedes Constatia is really bad in customer service