Coolpad India — service centre charged extra money with warranty period

I am ulhas mane,
Bought a coolpad mobile and it was under warranty. But when i visited service centre they charged me extra money 250 rupees forcefully and the behaviour of the employee was too rude and harsh.
They asked me if don't pay them than they will be too harsh with me.
Even they used foul language too...
I bought this mobile from amazon.
Details are given below:-

Order placed :- 31st october 2017
Amazon.in order number :[protected]
Coolpad note 5 (Royal gold, 32gb)
Imei number :- [protected]
Dispatched date:- 01st november 2017

I want an answer from the company as they behaved is right with customers according to you?
They even charged me extra and didn't services the mobile, may i know why?