Dealer refuses to replace an item under warranty

Good day

I bought a H-1 Bus from Hyundai Edenvale (Meadowdale) in 2020 and it started giving me oil leak problems. I took it back to the dealer to get it checked and they couldn't find the problem. The car was checked several times and they still couldn't find the issue until a new workshop manager was hired and he assisted me. The manager was told about the car. At the time the car was almost 5 months old. Since they couldn't find any issues i told them that i want my money back. The manager then opted to replaced the turbo and engine block after that when they tried to start the car, it wouldn't start. An email was sent to me requesting to check the engine only to find that engine was faulty. He had to replace the turbo and engine block. Both of these parts have a 3 years part failure warranty. I took the car last month (September) to the dealer for an oil leak. It was booked in for 4 days, I was told the leak comes from the turbo to the cooler. I had to pay +_ R2500 for the leak to be fixed. 2 to 3 weeks later the bus started leaking again, on the 3rd of October I took it back it was striped again. After that I was told that they have to replace the turbo because the gasket is leaking and the quote is R40000. I pleaded with them to give me a discount because I don't have that kind of money as I'm not working, I rely on the money I make from transporting kids to and from school. I was told that they cannot give me a discount . When I was home stressing about how i am going to get the money I remembered about the 3years part failure warranty. I started asking about the 3years part failure warranty which i had forgotten about. I was told that I don't qualify for a part failure warranty because when the items were replaced the workshop manager at the time used the goodwill code. When I asked as I didn't understand what they meant I was told it means I was unable to pay for the damage so the dealer offered to fix it for me for free. Now the issue is that the engine was not fixed out of goodwill. The reason the turbo and engine block were replaced the in first place was because I was insisting on a refund for the H1 since I had the H1 for less than 5 months and it had issues with the engine. When I tried to explain to them what happened for the dealer to fix the engine block and turbo the current manager refused to repair the turbo. May you please intervene and get me assistance.

Kind regards

CS Pharoe ***