Buying a car

Before you buy a car take a mechanic with who knows about cars and also if the car is worth the price, I bought a Chevrolet Aveo 2010 model for R4500 almost 280000KM on the car, had it a week and it gave problems, carnage fix it but I told the salesman that the car is losing oil from day one, went to eastern cape and had to check oil recently, not even 2 months after buying the car I gave it a service and replaced a waterpump, timing belt and after that a crankshaft seal because the oil came from there, they gave me a 1000km warranty, now the car oil rings are finish and I got a quote for R15000, this people really sold a piece of junk to me, the manager told me cars break and it's not a new car so I must fix it, is there nothing I can do