Yes, returns do happen.
I return books that aren't what they appear to be - not all erotica is labeled.
Yes, although very, very few, I have had some purchases returned. And yes, some were of my .99 short story. All of my children books have an underlying Judeo/ Christian ethic which results in a moral learned by the animal characters at the end of the book. Although explained in the book description and written in such a way as to not offend, a few have opted to get their money back, which I am glad they were able to do. Since we author/ publishers do not receive our royalties until two months after the sale, the returns are usually deducted before we receive the remittances for our work and the credit card is never charged. I believe the credit card is actually a back-up in case the book is removed from sale before the return can be issued.
Returns are a plague to me because of the type of thing I sell. I am in a different category than most book authors. I sell my own original crochet pattern designs which are doing phenomenally well on Nook and Kindle. Crafters like the ease of having their pattern in this form, rather on paper. But the big drawback is that they are easily copied, because they are only a few pages. Then unscrupulous buyers return the "book." Most designers do not allow returns on their patterns. In my other sites that I sell I can state they are nonrefundable, but here and kindle they can be returned. I don't have many returns, but when they occur, I am sure that is what the buyer did. If they legitimately want to return the pattern because they thought they were buying a fiction book named Sock Monkey Crochet pattern, I would understand. But it is clearly labled that it is a pattern, for goodness sake.
Well I guess, that is just the cost of doing business here, and I should not complain too much because I am happy with the results of my adventure on here. I just wish I could ask or find out why they were not happy with my pattern so that I might be able to improve it or correct what their problem with it is if they had a legitimate reason to return it.