Sad/unhappy/frowny face icon on my screen

Hello- I'm a new to iPod, just got 30G, fully charged, added songs, played all day yesterday fine, left plugged into usb overnight to charge, showed full green, ran for 15 minutes this morning and froze up. I followed the 5rs, tried reset, will not restore, does not appear on My Computer or iTunes, all I get is frowny face, then screen said please wait, very low battery, alternates with frowny face. I read in support that it may be a hardware problem- anyone have any suggestions or is only option to get it serviced, and if so, can it be done at genius bar at Apple store? Thanks for your help!