FBA received 0 units in shipment

I have a re-stock shipment that was received by Amazon, passed through Receiving status, and then Closed status with 0 units received/located.

I opened a case investigating the missing units supplying the waybill showing the size of the carton delivered and packing list showing the contents.

Amazon’s response was: “When we receive shipments with quantity discrepancies, we automatically initiate an investigation on your behalf for the items. As part of this investigation, we perform a second, physical count to reconfirm the quantity of the items received. Items are marked “Investigation Completed–shipment contents counted and confirmed” when we have completed. We have completed an additional check in response to your request. We have no record of receiving the following expected items.”

Does anyone have advice how we could proceed to perhaps submit a claim with Amazon for the lost units?