Fradulenece in car warranty provided how to take legal action

I purchased a car & I was promised 5 years warranty which is provided by them by extending the given 2 years warranty by the company. but they gave me only upto 3 years warranty on the car. on asking to the salesperson although he first promised for starting few days but later refusing to the company by saying he has promised me teflon coating warranty of 5 years. I have two witness , one itself is working on the car company. please help me in this matter as he has promised in my home also in front of my parents & also infront of his colleagues in showroom. How to take action?