After updating my iPod 5 to ios7, it's sound got muted. I tried to update/fix the problem by connecting it to itunes but could'nt. My iPod is giving the messag "your iPod touch could not be activated because activation is temporarily unavailable"

After updating my iPod touch, it got mutated. While updating it thru itunes it is asking to update the iPod. However when i try to update the message comes your iPod touch could not be activated because activation server is temporarily unavailable. Try connecting your iPod touch to iTunes to activate it, or try again in a couple of minutes. If this problem persists, contact Apple support at apple.com/support". I am trying to resolve this for many weeks now dont have any idea where to seek help from. Really appreciate a quick response from anyone.

Thanks.