How do you know it was this buyer? Were any other orders for this product fulfilled?
I know how frustrating it is to have negative feedback removed. But this just doesn’t fall under Amazon’s criteria for removal, no matter how unjust it is.
We’ve maintained 100% feedback for 13 straight years. When a buyer left us negative feedback we would send them a message asking what we could do to turn this into a positive buying experience for them.
They always made a request. Our reputation is so important, we will do whatever it takes to turn the transaction around. If they don’t remove the feedback on their own, we send the conversation to Amazon Seller Support and they have it removed.
I am sorry to hear that you are experiencing issues with an unfair feedback comment.
As @FunkyMonkey says, this one is unlikely to get removed using regular means. Maybe you could try escalating on Twitter or by posting on Amazon’s forum, here the senior Amazon staff may be able to help.