I would be concerned too if my iPod was not recognized by iTunes. I found a few resources that I think might help.
First, I recommend following the steps in this article to troubleshoot the issue of your iPod not being recognized in iTunes:
Once your iPod is recognized, I recommend reviewing this article for information about what content you can transfer to your computer from your iPod:
If you do need to have your battery replaced on your iPod, you can find service options at the following link:
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