Southgate Wheels sells unchecked vehicles

Just over a month ago I bought a Renault Duster from Southgate Wheels, they promised it was in a good condition. I told them I am a single mother and need a reliable car. I traded in my car so that I can save on installments and on fuel, it also had more space, so it seemed like a great idea. I week after I bought it the clutch started shuttering, I checked the oil and saw that it needed oil. After that I needed to put oil in every week. I bought the car from Thomas, after papers was signed, he was useless. I started speaking to the financial person. I was told that I can take my car to any RMI approved workshop, warranty will pay. My car has been at that workshop for a week now and it seems like it needs a engine overall as well as the clutch that needs to be replaced. How is that a reliable car? I also don't understand how this car is DECRA approved, so can you trust Southgate Wheels and DECRA? None of the defects was mentioned to me and also not to Wesbank, who is financing the vehicle. I have been without a car for this week and asked them if they can at least borrow me a car because I doubt it will be done soon, I haven't heard back from them. So I am assuming that I can't even visit family on Christmas day. Can't do anything with my child over the holidays because I have no transport.