Car fault

I bought a car from Hyundai South Africa on the 16 September on the same day gear number six was not working and on the windscreen there was about 3 chips had to take it back to be fixed, then the second week it was showing another fault it was break light and also the light infront is having a mist all the time then on Sunday the car stopped on the freeway all the gears were not working, now they say it my fault , i have not even paid the first installment.any adviced coz now i don't have a car but they are not helping me at all