my iphone 5s (ios 9.3.2) has gone silent automatically. The phone has no sound at all. All settings are ok, mute button is up. But no ring sound, keyboard click sound, even when i play music no sound either. Please tell me what to do?

So I don't want my phone to vibrate when it's on silent. I went to settings-sounds-and switched it to off where it says "vibrate on silent" however if i go back to the settings then to that screen again it's switched back to the on position and will continue to vibrate on silent. I tried...