Apple iPhone x 64gb space gery - DELIVERED PRODUCT STOPPED WORKINH WITH IN 12 DAYS

I have purchased appele x **gb Grey colour mobile on **th may **** and it was delivered on **th may *** from flipkart.
After using ** days i.e on ** june **** it was stopped working and i went to apple authorised service center to know the problem with device, after the diagnostic test they have confirmed that display need to replaced, i have contacted flipkart customer care helpline assistance for replacement and they are saying that out of return policy. am asking to replace the device not for return the device but they are not at ready for replacement. please help me in replacement of device or money refund.