Any of us who have dealt with this crap know how frustrating it can be, and sometimes it helps to rant online to an audience that's been through it too. I know I've been where the OP is - and sometimes it helps to rant.
Sometimes the smarter, rational approach isn't the best for us emotionally. Especially in a case like this where eating shipping isn't that big a meal. Heck - buyer MIGHT even back down.