How to remove an unfair and not true negative feedback?

[Anonymous]

Hey guys! This is Coco, am Chinese and writing from China office ! Is there anyone can help with my stores' negative feedback, i don't what should i do next!
We are new on ebay, with only 150 items and 95 positive feedback and 1 negative feedback. 
There's a buyer bought one of the item dated 12th Sep, and the location was China, i sent the same day.
10 days later he said not receive the item. i told him pls wait 5 more days regarding it's the regularlly delivery time. since the National Day approaching, so shipping company might not ship on time which is really out of our control; so  the customer opened a case, then we refund all money back. actually it wasn't delievered till 13th Oct.  
As a reliable seller selling good stuff with competitive price, i hope he can try our guitar pedal and give us a chance to remove the negative feedback.  So i asked my US customer send him another new one. a week later i send email to check with him if he received the second one, he said "no, send it right away!"  so we checked all delivery imformations, shows that two of them are delivered.  am not sure what does that means. As we all know how a negative feedback effect our store as a new seller. Is there anyway i can remove this feedback?

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