I'm not sure if this is a new thing or not, but recently I've noticed an exponential rise in the number of my books being returned on Amazon after they have been read in their entirety. I have been an author for a number of years and have been making a reasonable income from my writing with several series and a few stand-alone novels out there. Suddenly my income is dropping and I can only put it down to the increase in the number of returns.
Now, I don't mind the odd return if a reader gets a chapter or two in and realises the book isn't their cup of tea, but it seems a bit rich to return something if you've read it all the way through. Even if you didn't like it that much.
Is there anything I can do about this?
Yes, unfortunately this is a thing at the moment. It seems some influencers on Tik Tok have been telling readers they can return books after they have been read and that has led to a whole lot of writers feeling the same way you do. It is a flaw in Amazon's policy and they seem unwilling to do anything about it. And why would they? The download fee has already been paid and that is not refundable even if the price of the book is returned to the purchaser. And who pays the download fee? The author or publisher.
So it's a bad situation for authors who are essentially paying for people to "borrow" their books. Apparently it's even worse for people who have their audio-books available through Audible because people can return audio-books for up to a year!
In terms of what you can do, short of pulling your books from Amazon and selling only on other platforms, which is probably both rash and foolhardy given Amazon's market share, you're short on options. There is a petition going around to try and get Amazon to change its policy, but whether this will have much effect is yet to be known. But my advice would be to sign it even if you are doubtful it will make a difference. If enough authors sign, Amazon might be forced to take notice.
And talk about it. Loudly. Wherever you can. Readers don't necessarily know that doing this is costing authors. Readers don't think about the months or years it took to write that book and how little per hour the return is for the work. So make them aware. I'm pretty sure most readers would be horrified to know they are essentially stealing from their favourite authors when they return a book they've read.