Apple India — Camera quality and processing time...

Address: 110092

Website: Www.apple.in

Dear apple,
I have purchased iphone 7 plus a month back after loosing 6s plus. After using this set for 1 month, i realised that somewhere i mistaken by purchasing it, as i am regularly facing problems with its processing like-
1. Couldn't search contacts by name.
2. Side touch for changing tabs get slower or sometime doesn't support properly.
3. Fingerprint sensor responds just only 50% time.
.
I order it from amazon.
I afraid that whather its of gray market or original one.
Please help me out or otherwise i have to return it as very much disappointed of its quality