Xiaomi India — note 4 getting silent and network issue

Dear sir,
I have purchased note 4 in sep'17 and getting frequently issue of not receiving the voice during any incoming due to which i have missed so many important calls. After reboot the device it's working fine for few times and again facing the same issue even in a day i have to reboot the device 2-3 times.
2nd issue which i am facing related to data not working few times at same location where as other user's with same network are not facing the same issue. This is also getting resolved after reboot the phone.

Please support to get the same resolved.

Regard
Deepak miglani