Pathetic After Sales Service

I bought a new Hyundai Grand i10 from Hyundai Plumstead on 1 September 2023. I was very happy with the sales process, but their after sales service is pathetic. In May of this year after 9 months the car started making a terrible rattling like noise from the engine under acceleration. I booked the car in and they discovered that there was what they called a "ping" in the engine. Since then the car was booked in 11 times for this issue and all that's happened since is that the noise got louder and more frequent. They even did an ECU software update which made it worse. I went to speak to the Dealer Principle Junaid Daniels and he assured me he will come up with a solution for me and call me that same day. It's been a week later and I still haven't heard from him. He is avoiding my calls and emails too. I even logged a complaint with the Hyundai South Africa Customer Care line and got an automated response. I tried calling the Customer Care line and it just rings continuously. If I had known the service from Hyundai would be this bad, I would have never bought a car from them.