Phone won't turn off-volume doesn't work-home/sleep button activate voice control!

My iphone 3Gs will not turn off. When I hold the home and sleep button down, the voice control is activated. I cannot deactivate voice control. The volume buttons do not cause the volume to increase or decrease at all. I have reset and updated the phone to no avail. The warranty has expired. Any ideas or suggestions? It would be greatly appreciated!