BMW India — defective front tyre got burst

Address:

Lucknow, Uttar Pradesh, 226016

Purchased x1 from bow lucknow in 2017 july, have run approx 12000km and their was a complain in front right tyre of my vehicle since last 4 months (Pressure keep on decreasing every week by 3 points or more and bmw showroom was not able to detect a puncture), i was in regular touch with bmw guys here and 2 months back they fixed it somehow stating the problem is solved, i have always contacted the team in lucknow for any smallest assistance since i purchased. The guy specifically mentioned to me and my driver that their seems to be some inner defects or what in the tyre and that is the main reason and we will replace if required. Last week the tyre got flat all of a sudden at a speed of 20km/hr as i was about to park it and their came a 2inch crack on surface of front right tyre. Now when i send the vehicle to company they are reluctant to change it and giving lame excuses that you must have drowned your car into a big pot hole or rubbish etc.
I am owing other vehicles as well and this kind of thing has never happened to me before, is this about the 3rd grade quality being used by bmw in such a costly vehicle, what is the guarantee now for the rest 3 tyres in the vehicle, who will be responsible if an accident happens to me on a highway due to sudden bursting of tyre. Even after contacting bmw customer care their was no response of my 3 times calling and every time the guy said that we will contact you soon. Is this the kind of professionalism bmw lucknow is having. Morally this is unethical for a customer who has been so honest to the dealer here.
Had it been wear tear of the tyre i would have not even debated on this... This is shear case of manufacturing defect in the tyre by firelli and i want my tyre to get replaced free of cost by the company, over to you and waiting as usual