Xiaomi India — redmi note 4

I bought redme note 4 last week.It was going perfectly fine.But today while I was calling phone went off.Then it went ON and then display went OFF.I just can't think how should I tolerate when my phone's display went OFF that also after just 1 week.I just need another phone.There is no other remedy for this.I need a new phone of same category or else I will complaint against the company in the consumer court.