iPhone 5c call stopps / breaks in the middle
I Have an iPhone 5c 16 GB. When I make a call, sometimes the call breaks in the middle and I hear the last word of the caller in an endless loop for 10 to 12 times and than the connection is broken. I have already updated the phone, than reinstalled the phone and finally even exchanged the phone for a new one. Unfortunately the failure stays. I'm on the latest iOS version. The only way the phone can be used for a call after that failure is to shut down and restart completely. Appreciate any tips and help on this one.
IMac, Mac OS X (10.6)