Mechanical failure on newly purchased vehicle

After purchasing a vehicle from InspectaCar Gezina in December I have had endless problems and very little assistance resolving it. After driving the vehicle for 5 and a half months the motor has had a mechanical failure and the dealer principle is not willing to assist with repairs even though the vehicle that they sold has been problematic since it was purchased. The manager and dealer principal does not get back on any phone calls and emails and are very rude. Please can someone assist us with this matter as it is urgent