We've created this Forum Thread with some workarounds and advice to assist you in publishing you ebook.
I recently sent an email to Amazon asking to change the catagory of all my Fantasy books as they are listed there in Science Fiction which they obviously are not. I also gave them a list for each book showing the specific category tree that I would like each book in as well as the keywords I would like used as well.
What they came back with is this,
"I'm very sorry for the inconvenience you experienced in this case.
I understand you'd like to update or change the categories and keywords for your books "Angels Blood", "NIghtclans" and "Wolfe Pack"
The information shown on your Amazon.com detail page was provided by your publisher through a different channel than Kindle Direct Publishing (KDP). Unfortunately, we can't change information for books submitted outside of KDP and recommend you contact your publisher directly for assistance.
In order to get the categories and keywords updated for the book on Kindle store, please contact your publisher (Lulu.com) directly for assistance."
I have read here on the forums that others have successfully changed the categories by direct contact with Amazon since they have so many subcategories that are not available on Lulu. Not to mention that Lulu does not supply Amazon with keywords, so whats the deal?