MRF Tyres — The tyre got damaged with in 15days

Sir .
I H.sunil kumar, recently brought the mrf rear tyre at mrf showroom tekkali .srikakulam, A.P.
Now i faced issue With the new tyre and I just travelled 300km ... after that i found a small crack on right lateral surface . I am using mrf tyre since 10 years. But i never face such problems . While purchasing the tyres the showroom is not provide invoice copy also.
From my side i submitted the tyre for the physical quality check on 29th November. I got a call from customer service they told me that is not comes under a manfacturing defect..
I completely unsatisfied with their response because its a new tyre I didnt expect such a quality from mrf tyre .kindly look into this issue do the needful as soon as possible.