Faulty car sold to me by Nissan Melrose Ach claiming is brand new

I bought a brand new Nissan Qashqai in 2017 @Nissan Melrose arch. Surprisingly, I started hearing Finn sounds on my car, around June/July 2018, I then went to Nissan Melrose and I was told nothing was wrong with the car. I went again after 2 weeks, this time the oil got finished so quickly I had to buy oil a week after I took my car for service. I told them about the sound and the oil. The poured oil and told me to drive the car for another week, well then they told me it was engine faulty from factory and I had to bring the car for the engine to be changed around August and September 2018. It’s not a year since the engine was changed, now the electrical appliances are not working properly. Radio switch on and off. The battery that was manafutured in 2016 October is dead, like literally dead. Because the car does not change it anymore. Even when I complained I was told to bring the car and sort myself out with transportation. It’s not my fault that my car is broken I have been complaining since I bought this car. All I asked them is as a client, I don’t want to be disadvantaged when they fix the car, I want Nissan to provide me with a car I can drive. Since it’s them who sold me a faulty car under the pretendence that it was Brand new. If it was indeed brand new, why am I experiencing such problems in less than 3 years?????