I had the asame problem with my Harry Potter audio books. Pasted below is my email from iTunes support.
I have the first 3 audio books and was going to buy the others but as of today they are no longer appearing when I search on iTunes. I bought the first 3 audiobooks on iTunes in January 2012.
1) Make sure you're using the latest version of iTunes. It can be downloaded free of charge from the Apple website:
Note: Installing the latest version of iTunes will not affect your library or any items in your account that you haven't downloaded.
2) Open iTunes. From the Store menu at the top, choose Check for Available Downloads. You can also click this link to do the same thing:
3) Enter your account name and password, then click the Check button.
The missing item should begin downloading and appear in your Purchased playlist. If you receive an error message while downloading, try again after turning off any firewall or web-accelerator software that you may have installed. If the download process is interrupted for any reason, it should resume once you reopen iTunes.
This article provides information about resuming interrupted downloads:
If you don't see the item in your iTunes Library, please include this information in your response to this email:
- The name of your Internet service provider (ISP)
- The type of Internet connection (such as dial-up, cable modem, or DSL)
- Any troubleshooting steps you may have taken
- Any error messages you may have received