Topend Aunto sold me a problematic car

I purchased a car through standard bank from top end auto on the 14th of September by the 21 September just under a week of having the car... The car broke down... They collected the car and said they would repair the car however after talking to the manager he started blaming me and my fianc? for the damages which is almost impossible since we only had the car for 6 days and the damage was mechanical. Later he said he would keep the car if we did not pay half of the repair costs. I finally decided to pay. The next day after collecting the car the car broke down again but now the noise is on the motor and repair would costs thousands. The car has been driven less than a week of the month that I have the car and now stands in my driveway with the dealership refusing to give me a cancellation letter... I have now officially gotten CPA as well as scorpion legal services involved as the manager Reza miller has no business ethics and shakier the salesman shows no sympathy toward my problem