Car Salesman **** when selling me a car

I bought my Volkswagen Polo 6 on the 7th of March 2014 with 144 000 (odd) km on. When the salesman came to show me the car , he sonfirmed that the Cambelt has already been REPLACED, as my Father spesifically asked him this. Within the 3rd week of having my car , the \spanner"appeard on my dash - meaning the car needs to go for a Service. As i was still in my 6months of the Dealership being responsible for this"