Bridgestone Tyres India — tyre burst and become flat while driving

Address:

600018

I have bought tata hexa from tafe, chennai through my company, tube investments of india limited in august 2017. On 10th june 2018, when i was driving the car on r. K. Mutt road near adyar bridge, right back side tyre got burst and became flat immediately. I was shocked since the car is only 10 months old and tubeless tyres would not go flat. Luckily one mechanic came and changed the tyre. The i went to tafe on 13th june and they advised me to buy a new tyre since they cannot fix the flat tyre and it is not safe to use it as spare tyre also. Hence i bought a new tyre from them and paid money for the same. They raised a complaint with bridgestone and they rejected our claim stating "that tyre got impact by some external object damaged polycords and resulted in sidewall burst".
I want to register my complaint with bridgestone:
I have been driving new cars in chennai ever since 2001 (Since i came back from kuwait) but this is the first instance that i had experienced a flat burst tyre.
The hexa car is now and within 10 months how did the new tyre got burst?
I have been maintaining the tyre pressure all the time as recommended at 35 psi (Front tyres) and 36 psi (Rear tyres).
There is no way of impact by an external object since i have been driving on chennai roads under normal coditions.