Did you purchase the geek squad warranty with it? If so then return to the store and they will send it off for a rapid replacement. Otherwise you will need to contact Apple for warranty services if the ipod is still under warranty if its not then you will still need to contact Apple either via online or preferably a Apple retail store and get a estimate on repair costs.
----------ALWAYS check your purchased items for damage before leaving the store. If you never leave the store and check it in front of a employee it removes all doubt that you might have damaged the item.----------