I received my Samsung Galaxy s 4 today and I found that when I placed or received a call, I would pick it up or the the other party would and neither of us could hear the other. About one in a dozen calls could be heard and when I restarted the device, a call could be made and heard; but soon, it would be the same thing all over again. The same thing happened in Safe Mode and I've attempted many troubleshooting techniques like checking the SIM card and such. but nothing is working. Any advice?