There has been a glitch on eBay for the last couple of months where text in the section where you enter policy stipulations for returns disappears when you edit or relist an item. I'm thinking it's possible that may be causing some confusion.
This same problem is causing items to appear as available internationally when they're not supposed to. :<
I had the exact same situation very recently with a pair of sunglasses. I ended up leaving my seller a neg simply because she couldn't abide by her own auction terms which stated "14 days money back, buyer pays return shipping." She didn't have any stipulations such as only offering refunds if the item was damaged or misrepresented...but the seller tried to tell me that was her return policy when I told her I wanted a refund. I ended up having to file a case through eBay too, and did get my refund. I felt like leaving her a neg was fair due to her being unwilling to abide by her own auction terms, in hopes that I could possibly save another potential bidder from going through the same situation I did with that seller. I would not have left a neg if the seller had been willing to work with me in accordance with her return policy, but since I had to open a case when I shouldn't have had to, I felt the neg was deserved.
I agree with you. I didn't want to tarnish the seller's record, but I did leave a negative feedback for this reason. Rather than simply refunding me the money since I returned the item within 7 days at my own cost, he started badgering me via email saying "this isn't right, bla bla bla". I didn't deserve the badgering. I want to make sure other buyers are fully aware, before they buy from this seller.