Maruti Suzuki India — Amount discrepancy

Address: Industrial Area phase 1 Maruti Suzuki autopace

Dear Team,

I would like to take this case to higher authorities when we book a car on X amount if the ex-showroom prize will increase & then delivery should be on same X prize.
We booked a car ERTIGA CNG model in DECEMBER 2021 & They said estimated delivery should be in February 22 but the thing is now they're saying 10% will increase it almost 20 thousand difference in between at the time we booked a car.
My question is what is the main purpose for booking on time?
if booking amount & delivery amount is different.

I require mail id of the branch manager of the Chandigarh Maruti Suzuki showroom.