Tata Motors — Tata nano car milage problem

Address:

Thane, Maharashtra, 410208

I am Harish Konvilkar & i have use tata nano LX model,

I feel that i have done blunder by purchasing tata Nano petrol car, company declare to mention petrol car 25 km Average but My car is giving me 12 to 15 km average & there is no solution from the dealer TATA Motors

i have regularly complaint tata motor authorized service center in Vasai (Vijay Auto) they are making me fool they said that you just fill the tank of car we will check the vehicle i visited Tata motors four times but no solution given by the vijay auto peoples.& same done by tata motors customer care peoples.