Motus Select Used Cars

I bought a used car at Motus Select Polokwane on March 2022. I was charged a delivery fee of R6975.01 inc. VAT. I did not get a better understanding of the purpose of the fees as I went to the dealership to collect it myself. On the 21st October 2022 my car gave me problems. I could roadside assistance to help and they discovered that the problem is the battery. They suggested that I take the car to the dealership for assistance. I took the car to the dealership for battery replacement and they could not assist as they says it is not under warranty. I still do not understand why they did not replace the battery. I had to buy another battery for the car that I bought 6 months ago.