I'm so sorry for you. I can sadly say, after years of selling (outside Esty), some buyers just won't be happy, no matter what you do. I've had customers that had my heart & soul on a plate, I gave them more than they ever wished for (I'm a web designer on my day job), and they still tried to 'get some more' out of the deal. The funny thing is, that when I told them ok, I quit, you'll get a refund and let's call it a day, they didn't want to. They just wanted to complain. The thing is, that it's just 5$! You've spent more than 5$ worth dealing with this customer already. I think the best way for you is to keep apologizing, wait for the package to get there already, and after it gets there inform the customer that you've decided to give them a refund, and they can keep the package as well, because of "all they went through" (oh, dear god, the horror!). Maybe this way you won't get the bad review. Have the best of luck! :)