Jeep South Africa
Defective gearbox

I booked my vehicle in at Jeep sandton yesterday. The car is a automatic however when the vehicle is on an incline at the robot while in drive, the vehicle starts to roll backwards. This is unsafe as there is the possibility that i can roll into other cars. I was told by the mechanics at Jeep sandton that is happens with the CVT gearbox. This is not acceptable to me as this did not happen when I bought the vehicle as needs to be fixed.