Gear selector cable breaks mere weeks after purchase

Bought a Mini Cooper from them on 20 October. Less than 2 months later, the gear selector cable broke and I was left stranded on the side of the road. The maintenance plan they made me take does not cover this part. My insurance did not cover it. It cost R14000 to replace this part. I do not comprehend how this was not picked up in the Dekra report. Or the roadworthy test they said they did. Now that I have the new part, I can very clearly see how the car is MEANT to work. And how much was wrong with it. But their "reports" and salesperson persuade you otherwise. There is also a dented left door and no backboard. This was not declared to me. These people are dishonest. Do not ever buy from them.