Can't get my money back after buying car that brok

I have recently purchased a vw combi from lucky's star motors ,with a enjin and gearbox guarantee or 1000 km witch ever comes first... now the problem I have is that the enjin packed up within the warranty .... the owner Rasheed is refusing to give my money back he ...insists on repairing the vehicle witch I am not happy about .... what can I do to get my money back .... ? Please help