I checked my feedback today and found this: "The vendor was very unprofessional. I requested Stanard [sic] shipping, which permits tracking. She sent the book something like "book rate" or "media rate', which is cheaper and does not permit a tracking code. Although the difference that she pocketed was fairly insignificant, I believe this provides evidence of her character."
First of all, I did nothing wrong. I don't even know if the book was late (last I heard from her, we were still within Amazon's guideline of 14 business days). I found nothing on Amazon saying Standard shipping requires tracking, and they recommend Media Mail for books. So the problem, if there even is one, is that the mail might have been slow due to the holiday.
As for pocketing a profit, the purchase price plus shipping was $21.49, and I received $16.57 from Amazon. I also spent $2.20 to fax her the postal receipt to prove when I sent the book.
I started writing a note to her defending myself, and decided, screw it, I'll kill her with kindness. So I initiated a full refund. I believe THIS provides evidence of my character.
In the explanation for the refund, I wrote: "As evidence of my character, I'm requesting that Amazon send you a full refund. I was not seeking to profit by using Media Mail, but just following the method Amazon RECOMMENDS for standard shipping. In return, I hope you will remove my negative feedback."
You can leave feedback defending yourself, so there I wrote: "Buyer left negative feedback because I used Media Mail for Standard book shipping, which Amazon RECOMMENDS. Buyer said Standard shipping requires tracking; I couldn't find evidence of this. Buyer thought I was trying to profit and questioned my character. To show my true character, I asked Amazon to give her a full refund. I hope she will remove the negative feedback in return."
I'll remove that note if she removes her feedback.
Crazy, I know. But I am the LAST person who would penny-pinch on mailing methods. I care about my reputation a lot more than I care about money.
UPDATE: I called Amazon customer service, and spoke to a seller specialist, who said I did nothing wrong. Still haven't heard from the buyer and the feedback is still there.