My iphone 4s has no sound

My iphone has no sound.  My incoming calls can't be heard, the keyboard, music....nothing.  I tried every suggestion that has been posted.  I removed the SIM card and put it back.  Powered the phone on and off.  Pushed the volume up and down buttons several times.  Blew out the headphone jack and put the headphones in and out several times.  I can hear music through the headphones, but that is it.  (And for those individuals that posted make sure the button on the side is in "ring" mode...thank you...that was the first thing I checked). 

I wonder if everyone who this problem and tried all the troubleshooting had to return their phones?  Did you have to send it in to Apple?  How long did it take to fix?  I have a hard time being without a phone, I run my business this way.  If anyone knows, please let me know.

I think it is pretty bad of Apple when you pay so much for a phone and so many people are having this problem that they don't figure it out and fix it.  Maybe a recall??  Sounds like too many of us have had this problem.