My car has not been repaired properly while under warranty, and they shifted the blame

I bought my car, VW Taigo R in July 2024 in Hatfield Pretoria, I have been servicing my car at VW Stridjom park ever since. I don't remember the exact time, it started to give me this notification of error start or stop which came and go, when I took my car to service I reported it and I was told me that it was due to the 95 petrol I'm using, I must use 93, which I did and it disappeared for a while then came back, which made me return to 95, then it disappeared, on the 23rd of September 2026 I took my car for service, my car was no.*** on that day but when I arrived at around 15:00 I was told they are still busy with my car, until they gave me my car at around 16:00 when I asked what is delaying my car because the cars that came after me have already left. On the 9th of October, last Friday when I knocked that notification came again, then I thought it will disappear as usual, after driving for about 5-8 km the car started to lose power, when I stop at the traffic lights it was hard