Context: shipment received on May 17st but took Amazon until after Prime Day (almost 2 months) to allow me to open an investigation. The dates keep getting pushed out further and further. After being able to open a case after 2 months, they come back saying "they confirm no shipment/unit was received". I have proof of delivery and everything

My concern is, how are they so sure they will get a hold of a small shipment after 2 months and now they decided to not "investigate" further. Can someone please help? My case ID is 15658612341

I have lost shipment with Amazon before, in which they are able to reimburse me back, but not this time, not sure if it's the long time leading to Prime Day that made them unable to track my shipment. Either way, I still need to get reimbursed. If someone can help, I would hugely appreciate you!