Webuycars not abiding by the CPA

I purchased a vehicle last week Wednesday (3 July). Vehicle was gold rated, Category B with a valid Dekra report. 2 days later ( Friday 5 July) the car suddenly lost power on the highway almost resulting in a catastrophic accident. Webuycars collected the vehicle same day and on Saturday (6 July) they notified me the vehicle had been fixed and that the issue was faulty sparkplugs. Sunday (7 July) arrive at the Midstream branch and before we could exit the premises, the car lost power again. So in totality I drove the car for 2/6 days and it has been in repairs for 4/6 days. This car clearly has significant mechanical damage making it undrivable.

When I asked for a refund; I was given two options. Allow webuycars to confirm if there is a mechanical problem, and to fix; or cancel the purchase and forfeit R5k.

As per the CPA this vehicle is clearly not in a condition to perform its intended purpose. Also, as per the CPA I have the choice for a refund or repair. Webuycars are a bunch of ****mers who have no respect for the rights of SA consumers. The fact that they need to ascertain if there is a mechanical problem for a car standing with them and that died on their premises is complete insanity.

I do not want this vehicle anymore (reasons listed above) and require my full refund. I cannot be charged R5k for having the vehicle in my possession for 2 days!