Vechile not in good condition

On the 20th of I bought a car from Gustav Auto (Shelly Beach Marine drive) in Durban, came back to Nelspruit in Mpumalanga. I went to our local town on 28th September and the car gave me a problem with gears, they were locked and didn't know what to do. I the called Gustav Auto for assistance with no luck they said I was the one who caused the problem. I the opted to go to Land Rover in Nelspruit and they diagnosed it and said there was a ELECTRONICAL FACTORY FAULT < had to pay R500.00 as Gustav Auto refused to help me,was the adviced to take the car back to the dealers. I am really in need of my car and require that Gustav Auto helps me as promised on the contract, nothing pains more then paying a for a car you are not driving. I last drove my car on the 28th September up to date. Kindly assist me with this matters. Thanks