Nokia India — i have ordered nokia 6 phone last month and phones gets restarted often, from past few days one hour once.

I have got an nokia 6 phone from amazon last month and my phone gets restarted oftenly, from past few days one hour once, please do help me in this. I am hard core fan of nokia handsets and after the release of this new android handset, i was very happy and ordered this phone, but now it is pissing me off with it's weirdest behaviour of getting restarted every hour and especially when i am making an important calls. I request you to look in to the issue.