Hello! I recently purchased a set of iBeats. When I took them out of the box and tried them they seemed perfect. I checked the volume control and it worked fine. However, when I tried again a minute later the volume control was not responding; the microphone wasn't working either. I took them back and got a replacement pair. The EXACT same thing happened again. The play/stop button works but not the volume control or the microphone. I have no idea what's going on. Help!