Bad Customer Service

I bought a Hyundai Venue in Hyundai Eastrand. Collected the car on Saturday and only to find that the drivers seat belt was not working and it didn't have petrol. Khumo advised me to take the car and she will pick it up on Monday morning to fix the belt. I went to Eastrand Mall and the car didn't want to start and I was stranded for 2 hours before Khumo came with her husband. She also tried to start it and it didn't work until her husband open the bonnet and fiddles with the battery bolts. then the car started. initially i wanted to buy Hyundai Creta but she advised me of the Venue because of the interest rates. I don't want the Venue anymore because it is not safe and it is not in a good working condition. (CPA). Car was collected today and when I did the follow up she says that she is waiting for her Manager to approve the change. I need answers and can you cancel the deal and i will go somewhere else.