Worst Car and Worst service

My conversation with mahindra Company and still no reply from them.

Hello Sir/Madam,

My self Tushar Patel from Ahmedabad, Gujarat. I had purchased mahindra Quanto model C-8 vehicle at 23-OCT-2012, from "Punjab Automobiles (india) Private Limited". I always given this car for service regular basis. I am attaching all invoice records with this email. Before that I had a Maruti Wagon R and used till 4 yrs and sell it. So no chance about my driving skill. At Nov-2014 in car had a issue and given to Punjab Automobiles and they said having issue in engine???? wow, I think all car segments having a Indicator alert before when any issue arise in engine but this car never and we had no choice at that time. I had also ask for warranty but its already expired and I asked service manager to repair engine and solve all issues and then ask for warranty for 2 yrs for engine but at that time they said why you want to extend, after repair engine we will already given 6 months warranty after 6 months, you can extend for it. No need for now. Now what happen, my car also have a issue like water leakage issue from radiator. This issue we already faced when engine have a issue. when my engine had a issue in Nov-2014 at that time same issue I faced. So I asked for warranty before 6 months completion so now they are not agree to give extend warranty. So now I am afraid for this car again.

For avoid confusion, I was thinking to show this car to different service provider for better resolution. so for diagnosis, I binged my car to "Sheetal Motors" at 25 july 2015 and they said in your car have a radiator issue. You have to changed it. but I have already changed radiator at 19-Jan-2014 again same issue. So I again went to punjab automobiles and those guys said, in car radiator is ok but heating coils have a issue. so you need to changed that and charge will be around 12,000 INR. Wow what a rubbish things are going on? what should I have to do??? who is correct, Sheetal motors or Punjab Automobiles? There are only 2 providers in my city. So I really confused about it.Seriously this car gave too much headache. No body answer to me even I asked to customer card but never get any single reply. now tell me what should I have to do?? 
-Thanks, Tushar Patel Mo: +91-9825 XX XX XX.