Audiobooks (and tones) are (and always have been) a one-time only download - if you want to redownload it you will need to pay to do so. Have you not got a copy of it in the Books (Audiobooks if using an up-to-date Mac) section of your computer's iTunes library, or on your backup of your downloads/library ? If not then you can try contacting iTunes Support and see if they will grant you a redownload : http://www.apple.com/support/itunes/contact/
If not already doing so you should be backing up all of your downloads, you are only guaranteed one download of any item (apps, music etc could be removed by the rights-holders at any time)
As these are user-to-user public forums I've asked the hosts to remove your first screenshot from your post as you've included your email address (and your postal address) - it's not a good idea to post it on any public forum, unless you like spam email.