Apple India — My mobile phone in out order

Address: Sonipat, Haryana, 131001

Website: www.apple.com

Respected authorities, my name is sandeep i am from a middle class family sir some days back i purchase i apple mobile (Iphone 5s) on 16, apr-2017 for my son its price was 18, 500 rs sir now this mobile is not working properly its home button not working in a good way and its now locked and not taking the password. And main problem is that its heating too much and no battery backup.
And sir today went to that apple store from where i purchase this mobile they said "we can not help you for button" and they ask money to unlock mobile password.
Sir i am not a lawyer so i don't know too much low but sir i told my problem in simple and straight language. So please help me i can afford this loss.