Not happy with the service never enjoyed my car

I bought a Nissan Np 200 3 weeks ago I am not happy with their service. I drove it for 2 weeks the Staring to smoke black took it to the RMI they said the injectors it's damaged. The car it's under warranty they not willing to assist me they want me to pay for the repairs.the it's under finance now I pay for a faulty car . Trying to contact the sales person he is not picking up my calls.