OK if you only have 1 bad feedback out of 50, and that's why your feedback is 98%, I would take that into consideration. But if someone has 500 transactions and 10 negatives, then he would be 98% too, and I would not buy from him. If anyone receives 10 negative feedbacks, he is doing something wrong, no matter how many positives he has. After all, there are plenty of sellers who have tens of thousands of positive feedbacks and NO negatives.
Also, did you describe
why the box was defective? I don't think just saying "defective" is good enough --- You should say which functions/parts are defective. Maybe you already did, I don't know.
By the way, I hate when people say "International shipping as defective". There are a couple German sellers who say that, and it cracks me up.
Why would a box be defective if shipped internationally, but not if it's shipped domestically? And it isn't like those words would protect them from a claim anyway.