My phone ringer and text message alert sound are intermittent. Not just on the iPhone6, but previous iPhone models and previous versions of iOS as well. I flip up the switch on the side of the phone, I hold the ringer button until it is all they up, and then I swipe up from the bottom and slide the volume button all the way to the right also. Even so, sometimes my phone chimes when I receive texts and sometimes rings when I get phone calls, and sometimes not at all. WTF am I doing wrong?