Very Bad/ No service

So I bough a opel opc from NTT Volkswagen, the engine light kept coming on and I took the car to GM centurion. They did check this and indicated that it is a faulty water pump. They changed the water pump and the light kept coming on, so I insisted for them too come and fetch the car to have a closer inspection. They said that there is a engine fault and its my fault(had the car for a month). I bought the car in that condition without me knowing. After a long and hard fought fight they eventually said they will repair the vehicle. The repair alone took about 2 months and allot of my money went to alternative transport to get to work. Now they will not release my car until I have paid R10 000 (I did suggest a monthly repayment but they did not accept this as they want the money in full before I get my car back)<br> <br> I did not know about this payment as I would have had the money if they told me before hand. They also said that they will pay everything in full. Witch is not the case and I am still without my car. Very bad from the NTT group and I definitely would not advise anyone to purchase a car with them.