Faulty Haval Jolion

I bought a Jolion Super Luxury from this dealership in December 2022. The car is dysfunctional, it just shifts the gear to neutral while driving at a very high speed and afterward refuses to start. On 27 Feb, I requested a diagnosis of what is happening with the car, and the Service Manager (Stoffel) advised me that nothing was wrong/faulty with the car after he claimed to have checked everything. On 8 April, I had a similar experience where the car shifted itself to N while on D7 and then refused to start. I took the car back to the dealership and then requested on 12 April 2022 for the car to be replaced or refunded. Up to today, I haven't received any response from Izak (dealership manager). I am supposed to be enjoying my new car, but I am stuck with a courtesy car that has a slow puncture. I would not advise anyone to do business with this dealership