We're in a similar situation except with Amazon being the one banning our books. I am the owner of FAKKU, an English publisher of erotic manga (Japanese comics). Despite there being a category on Amazon for our specific material and previously receiving approval to list our books behind an "Adults Only" flag, our books have been banned.
If you're wondering what that looks like from the customer perspective, you can see (or not see) our banned best sellers here: http://www.amazon.com/Best-Sellers-Books-Erotica-Manga/zgbs/...