Review is not removed even though mistake is committed by Amazon

For Order No 402-0453096-5907525, buyer was delivered only 1 of 3 quanitites of our product. Amazon has sent me the refund of 793.62 as per the Lost and Damaged Reimbursement Policy and Returns and Refund Policy for the mistake they have committed. But the customer has given me a 1 star rating on my Seller profile. When i approached amazon for removal of this feedback, Amazon seller support says to request removal from the feedback removal page. When i click on feedback removal a message immediately appears saying the feedback is as per amazon guidelines and cannot be removed. Also the case cannot be reopened. as already 5 days have elapsed. I want to know what is the fault of the seller and why the seller cannot request removal of feedback even though he has not committed the mistake. Is there any solution for this?