Maruti Suzuki India — nexa baleno sigma model rear power windows

I have taken Baleno Sigma (Petrol) model on 30th Oct-2019.
In that, there is only front power windows and manual windows at rear. I want them to change to Power-Windows. But, NEXA bluntly denied this.

As far as I know, All other Car models of Maruti Suzuki like Wagon-R, Swift allow having power windows at rear with the additional cost of Accessory-kit.

So, why not for Baleno.Also, these people threatened us not to install power windows at the rear from outside as warranty of our new car will be hampered.

I want that NEXA should give us kit which provides power windows at rear and I am ready to pay the additional cost.