I had a recent incident where the description of the item (sizing) was different to my interpretation. (ID v OD measurement) Anyhoo the wrong size turned up and I emailed the seller. They very clearly explained their interpretation, and I explained mine. Appeared there was never going to be any close agreement.
We weren't talking sheep farms in terms of $$'s, so I took a slightly different approach and said.
OK, understand, maybe state that in your description in future and I would get the right size.
I then said, what to do as I don't want to have to leave negative feedback?
Then all of a sudden they had a change of heart and posted me the correct size at no additional charge.
Depending on the seller and the value involved, sellers possibly get penalised for negative feedback from what I understand and this seller didn't want that.
I also posted back at my expense ($3) the incorrect item and all were happy.
Moral of the story is mention the word negative feedback and see what happens.