Hi
Apple accessories - including EarPods that are supplied with an iPod and those purchased separately - are covered by Apple's Limited Warranty against defects in materials and workmanship, but not against accidental damage or misuse.
If you believe that your EarPods qualify for a warranty replacement, contact Apple Support, make a Genius Bar reservation or visit an Apple Authorised Service Provider with a view to having them checked and to establish your available service options:
- Contact - Official Apple Support
- https://twitter.com/applesupport
- http://www.apple.com/retail/geniusbar/
- https://locate.apple.com
Otherwise, you will need to purchase a new set.