Apple India — Phone hangs

Address: Bijapur, Karnataka, 586103

My phone 6s hangs thrice n when searching contacts it gets struck. Everyone said iphone never hang n struck. Same problem when i open camera. For this i need solution or else the brand apple will loose its image i[censored] will not provide solution to this. I m using it since feb 2017. Initially when camera got struck i told this to seller he said u will get updates n will b resolved