Terrible service from BMW South Africa

I bought a 2019 BMW X1 in January 2020 from BMW Johannesburg South. On the 18th November 2020 while driving on the highway the sunroof exploded. There was a huge bang(explosion) which could have resulted in an accident. I then took it to a dealer(BMW Westrand) who logged the issue with BMW South Africa. I'm now being told that BMW will not be held liable as it was external forces(stone chip) What external forces? It seems once you've bought the car they no longer care. There's a problem with panaromic sunroofs but obviously BMW will never admit such. I spoke to Allie from Customer Services who cant assist, I was then transferred to Kaz Pillay who doesn't care and told me to report it to Motor Ombudsman. So disappointed in BMW.