HP India — brand new laptop hard disk repaired within one month

Address:

Pune, Maharashtra, 411007

I bought hp laptop for my brother on 17/11/2017. From croma pune. Which stopped working within one month.
Not knowing, what happened. My brother took it back to croma. Where he was forwarded to hp customer service.
That person came & repaired it, saying the hard disk is faulty, so he changed it. & informed him that, one cd will come in courier, which is still not come.
But i think i should get a new laptop, instead of faulty laptop. I tried their email, but everything getting bounced. Pls. Let me know, what to do?