iPhone 4S not making noise

My iPhone 4S suddenly decided that I can only have sound if I have headphones. I called apple to troubleshoot and was told my warranty expired 6 days ago and that it is a hardware issue. I also upgraded to iOS 7 two days ago. However, when I try to turn the volume up or down it shows no volume slider for any video, audio, or game apps. It shows no volume slider for ringers or tones. My ringer does work for incoming calls. But that is the only sound I get on my device. Has anyone else had this problem? Any help would be greatly appreciated.