不用你退啊。這是FBA訂單，是亞馬遜在處理、在發貨。應該讓她自己聯系客服（而且訂單是FBA的，所以他去開AZ的話，對你沒有影響）。
最關鍵的是，你確定他已經退貨了？不是騙你？
建議開case向Seller Support問清楚，再舉報買家威脅你

可以發類似這樣的回復給客戶：
I'm sorry for your inconvenience and I empathize with your position, but please understand that this order was placed via "Fulfillment by Amazon" and we are required to direct inquiries on such orders to Amazon.
In order to offer you Amazon's quick delivery capabilities, sellers who use Amazon's fulfillment program also hand over control for all service-related issues on those orders. Although I realize its inconvenient for you, and I do apologize for that, Amazon dictates that they must manage any return or refund issues you have.
It appears that, unfortunately, the Amazon rep you spoke with gave you wrong information.