My phone is not able to make calls. even though here is a full 4G network.. good data speed. I am able to send & receive SMS, but no phone calls are made/received. There is some 4G netwok call settings ISSUE in the phone. I have ported to Airtel from Vodafone. The issue is same. In the same netwok area, my SIM in Samsung phone works well. Please replace my phone. Thanks in advance.