no refund or exchange for faulty goods

I bought a gomoto fluxliner 150cc on 12august 2015 brand new <br> I have had issues with it sincethe day I bought it.<br> Brakes failing, not starting, speedometer not working,lights falling off.<br> U have been stuck on the side of the road more times to mention. <br> Bigboy south Africa refuses to exchange or refund me...<br> This is unacceptable