If you didn't use an ebay-generated return label you'll need to contact ebay and ask them to add your tracking number to your return case. Go to My eBay and click on "Help & Contact", top left. Scroll down to "Contact Us" and click on that. Then select a topic, the nearest or any topic. On the next page, on the lefthand side you should get a link for "Chat with us". You may have to change subjects until the link comes up. They will still help you.
