Does anyone know how to fix an IPHONE 3GS with NO SOUND AT ALL and it keeps on GLITCHING and REBOOTING?

So it all started when I brought this new charger for my iphone 3gs and iphone 3g, then after a week I noticed that my iphone keeps on glitching then reboot, but the sound's still okay. After a week again I think, I accidentally DROPPED my iphone 3gs and I'm pretty sure it hit the ground so hard that there was NO SOUND AT ALL even with the headphone's on, as in TOTALLY NO SOUND! I've tried everything, rebooting, updating it to IOS 6.1.3, etc.. but still, no sound! Plus the glitching then rebooting ****** me off! I'm not sure if the charger caused the GLITCHING and REBOOTING but you see, I have another Iphone , an IPHONE 3G and I both used the same charger for the two Iphones.. After a week, my IPHONE 3G started to GLITCH and REBOOT same as what has happened to my IPHONE 3GS.. but the difference was that when my IPHONE 3G started to reboot, there was a logo saying "Connect to Itunes" so I did what it said then it was fixed! PLEASE DO NOT BE CONFUSED. I'm asking help for my IPHONE 3GS, I just said a little about my other IPHONE 3G. Thank you soooo sooo much if who ever reply or help me!

by the way.. I'm sure the upgrading thing from IOS 6.0.1 to IOS 6.1.3 does nothing with the "NO SOUND" thingy on my IPHONE 3GS..

THANK YOU!