I have had my Nexus 4 now for about 1 month from expansys and on T-Mobiles network. At first the phone worked flawlessly with no hiccups. Now for some odd reason I can't seem to place or receive calls. My phone rings but when answered there is no sound coming or going. T-Mobile has checked it out and ruled out the possibility of it being their service. There have been a hand full of times where I have been able to speak with my wife and once from a wrong number. I have ruled out the recent software update to 5.0.1. I have received a call that worked both ways on both KitKat and once on Lollipop. Any help is greatly appreciated. Thanks to any one with useful advice in advance.