hello, new seller and I don't know what's the best way to deal with this. Customer claims didn't receive package. But USPS tracking says it was delivered 10 days ago. I bought Amazon shipping label. Customer is saying their address cannot receive USPS shipping, but they have a parcel box for USPS. They say they have this issues with USPS frequently but not with other carrier and she is sure I will receive the item returned back. It doesn't make sense to me, I don't think I will receive the item back. What now?

I checked some inventory and was surprised to discover 50 units just missing. I was unable to see what had happened to them so I had Seller Support call me. I was told that they got converted from FBA to FBM due to needing a hazardous goods statement update. I asked why I wasn't notified of this and she told me I would have received an email. I searched my desktop email including spam and bulk mail and found nothing. I searched my email online and found nothing. I asked the rep where I could see this alert in my Amazon account. She said I cannot see the alert in my Amazon account, only from the email (which I didn't receive). I asked her if she found it strange that alerts could not be viewed directly in the seller account. She said no, she does not find it strange. I told her I am concerned I may not receive other email alerts if we cannot explain why this happened. All my notification settings are correct with the correct email address. I find this all very strange. So here I am. Has anyone else had this happen recently ? This is my first time back at the new seller forums in a while....

We have reviewed this feedback and found that it is not in violation of our guidelines and has been retained. To request further review of this decision, re-open the case in Case Log.

Well I cannot re open the case because I already make one neither appeal it, the customer gave me a bad review saying that she never receives her order but when you check the tracking info she did. Amazon return her the money, I have the bad feedback saying that she never receives the order, but also she said that the item came defect and is affecting me on my account health. How can I appeal the feedback ? please help