Absolutely useless and bad business practice

I bought a car from We Buy Cars in Pretoria on the 18th of August 2017. The car has a flat battery and a faulty gearbox, they only disclosed the problem of the battery. When I stopped at the security gate on the main entrance on my way out, the day I bought the car, the car started not getting on drive (D), but it was reversing. I went back to the front door, the sales person and other staff members tried to assist but failed, hence they proposed that I buy a new battery, which I did the following day (19th of August 2017), but still the car couldn't get on drive (D). On the 19th of August 2017, nobody really cared, they were too busy to assist me. Furthermore, they refused to refund me my money, they indicated that I should sell the car to We Buy Cars at R90 000 of which I paid R104 000 for the car. Another option they proposed, was for me to take a warranty of nearly R9000 and get my car fixed after 30 days, which I did. Unfortunately, the warranty is not covering everything, there is a shortfall of nearly R32 000, and We Buy Cars is refusing to pay that shortfall because they say I bought the car cash. The car has never been at home, it's still with the service provider in Silverton waiting for payment so that they can fix the gearbox. I bought the car on the 18th of August up until now my car has not been at home, and We Buy Cars doesn't want to assist me anymore.