iPod won't mount - HELP

[faeiry]

Hello
I have had my iPod classic for about three months. I bought it as a refurb straight from the Apple uk website. Just recently it has seemingly malfunctioned as it won't hold a charge any more. When I plug it in the wall - it's fully functionable and says it's charging, but as soon as I pull the power cable out - it goes dead again. It won't mount when I plug it into the MacbookPro, or my old PowerBook. Via USB cable it shows the black screen with "charging please wait message".. but no matter how long you wait (all day) it never charges or mounts. I have also tried with a firewire cable in both machines, hoping the more power might help, and it does but not enough.. Via Firewire cable it shows as charging but the iPod remains unmounted.

Disc utility can't detect the presence of the device with either cable.

The annoying thing is I have a lot of important work data on the ipod and I'm afraid if I send it to Apple to be repaired (or replaced) as it's I assume clearly still under warranty, I will lose everything?. Can anyone offer any advice? I have tried resetting, and doing the diagnostic test - but nothing seems to work - I just can't get the thing to mount on the computer. I just need to get the data off - and then I'm happy for it to be repaired, but I am not sure how???!

If anyone can help that would be amazing.