iPhone 5 Not Disturb function locked

I used the Do Not Disturb function on my iphone5 several days ago and ever since I turned it back off I can't get any sound notifications for calls/texts/reminders etc. and I also cannot hear Siri's voice when I activate that function.  The Phone seems to be locked in the mode even tho the setting is now off.  I have done all the usual checks to remedy but nothing has worked, ie checked all the sound settings; turned phone off/on several times; synched at iTunes etc etc.  Testing sounds works fine and using sound apps like iHeartRadio, Songza etc. are fine. I can hear everything in Sounds Settings and vibrate works fine.  Any suggestions?

Thanks.