Amazon lost half of my shipment

Hello,

I am starting to be very concerned about Amazon inventory receiving process. They lost 13.5 kg of inventory from 29 kg shipment. This is not the first time they did it. Moreover they don't care about eny evidences (POD, invoices, weight records from carrier) that the items were delivered and just keep telling me the "shipment contents counted and confirmed”.

What can I do? This is extremely frustrating.

Shipments: FBA15JXZH9GS

Petr