Backdoor cor at mma cars dont get caught!!!

I saw an advert for a mercedes c63 on the internet. I drove to the dealership and asked to see it and was told to come back as the car has some scratches and was out for polishing. When it came back i looked at it and wanted to buy i arranged my own finance and was told by the salesman Calvin that this would he fine. When i was approved i was told i cant arrange my own finance and that they will do it. Disheartened i agreed. I was told by the salesman on the day of taking delivery that i need to add a warranty and additional charges were to he added but i was refused a discount on the vehicle. His exact words "if u dont want it no problem i have another buyer" On day of delivery i was told to note on paper what i found to be wrong and this will all be fixed for me. I did so only to find out i was ******* into noting im aware of the faults and take the vehicle as is. The car passed a dekra cor with no jack wheelspanner and triangle!!! How is this legal??? I took the car back to the dealer and it sat with them for a month awaiting a pipe for repair. Its since been back for the very same repair 5 times and its still not fixed. They call their workshop a rmi approved workshop but cant fix an oil or water leak. Further to this when i got the car back my rear tires were torn from them doing wheelies and rims badly damaged with chunks out. Engine covers broken dents on the body and while driving the sump guard flew out. I called the dealer principal mike but he refused to take my calls. I had 2 fix it myself and keep going. I was then told that im ungreatful as they helped me when they didnt need to so they wont fix anything further. Also this car was accident damaged and i was told it was not by mike himself. It has pirate and 2nd hand parts that are not even ment for this car!!! How did dekra pass this car??? Buying from them was a nightmare!!! I advise anybody to stay far away. Rather go to smd and buy a smashed car you will be happier. These guys put glue to fix broken parts.