Apple India — I'm complaining about my 45 days old iphone x

Address: UB City, 19th Floor, Concorde Tower C, Vittal Mallya Rd, Bengaluru, Bangalore, Karnataka, 560001

I purchased iphone x from flipkart about 45 days back. There was a defect in the body of the device (Rough finishing of the frame from upper side and a little gap between that edge and the back glass) which i failed to notice in the initial days as i wasn't expecting such a poor quality from apple and didn't give much time thoroughly checking the device. Approximately, after 30 days o[censored]sage, i noticed that dust has accumulated between the upper edge of the frame and the back glass. It was then that i noticed this gap and poor finishing of the edge.
It has been 15 days and i've been visiting apple authorized service centres again and again. Every time the representatives change their statements and fail to provide the complete information.
The representatives redirect me to the seller and the seller to apple.
When i visited the store for the first time, a representative admitted that the issue is a manufacturing defect and that everything including water resistance is intact. When i asked them for a job sheet, the report they gave was a complete disaster. They categorized the defect as a cosmetic damage and denied any service.
The back glass is intact, there is not a single scratch on the device, let alone any dent, not a single drop and they reported it as if it was me who caused the defect. This is just not acceptable.