Faulty Hyundai ix35 CDRI 2.0Lt 2011 model

I bought a car from dealership in December 2024 it now about 5 months since I bought it, but my problems started in the first week of February 2025 (1st I experienced hard start on this car when is hot, 2nd I noticed oil leak from engen bay, 3rd the car had a small battery in terms of size, 4th I took the car to Hyndai Rodepoort for service but to my suprise they find out that the issue of hard start might be that the glow plugs are faulty and they also told me that the heater system of the car has been breached meaning this car has no heater in case it is cold therefore I can not warm myself or my family during winter. All the above I have mentioned it to the dealersjip grom the beggining to the end. Lastly myself and the dealership decided that I bring the car back to them such that their machenic can have a look at it and upon its arrival they will advice of the way forwad, according to them he has diognosed my car and found out the 3 deseil injectors are faulty mind you Hyndai Rodepoort had diognosed the glow plugs as faulty. Now they are telling me stories like I must fix my car on my own as they sold me a moving car and not a non runner as it now or face the fact that they will re avalute it and buy it back as a non runner. Please help me as I am a pensioner who was looking to have a reliable that can take me from point A to point B. Your responce in this regard will be highly appreciated.