Apple India — iphone 5s network drop and heating up issue

Address: 560095

I've purchased the iPhone 5S in the month of Dec 12, 2016. When I tried to install the latest version of IOSon Jan 31, 2017, the phone got crashed. I did contact the customer care on that day and after spending the whole night, it got working again. But I had a problem with the instrument since the new installation. The calls were dropping frequently, the signal strength was poor and hearing the cracking noise during the calls. Though I leave in center locality of the Bangalore city, there is no reason for the network problem. I was using a BSNL connection for last ten years. But I thought it to be a network problem, I switched to another service provider i.e. Vodafone. But even with this new service I had the same problem. So it confirmed that the problem is with handset. I went to the Imagine store in Bangalore for the repair. They tries with the Reset Network Settings, but it did not worked. They asked me to restore the phone using the iTune. I did the same, but even that there is no result. Still the network is dropping frequently.

It is just a year and three month since I've purchased the iPhone. I can't believe that the handset has been out of order now. This is totally against the reputation of the Apple Products. I am shocked. The problem has started from the last update of iOS.