Amazon India — I want replace of my mobile

Hi this is Dinesh kumar mobile number : [protected]
I purchased mobile iphone 11 in amazon oct 2021 and i had prblm with mike in month of dec 2021 i reached to the nearest service center they accepted the mobile to check the prblm after they digonized they found unauthorised modification has been done how can it been done as we have done it apple has given us clear information and denined letter for the service
Amazon has given us used mobile is this the way amazon treat people just in two months problem has identified amazon is a fraud company selling the mobiles which was used in lower price i attached the denined letter from apple