Amazon lost a case shipment of 150 units when tracking and their own website say they received it?

It's been 2 months since the shipment ID shows delivered to Amazon's hederson warehouse, and the inventory wasn't ever checked in. We've lost so many sales because of this! We sent in a small partial case of like 50 units, because Amazon pre-sold based on that 150 unit shipment and we can FBA orders with 1+ month backlogs that were not shipped. Once they received that 50 unit shipment, they used that to ship the backlogs and the 150 unit case is still missing. Retail value of about $3k.

We then sent in another shipment (after the partial 50 unit one) of 150pcs. This shipment was delivered over 2 weeks ago and UPS tracking shows delivered, but Amazon's status doesn't show its been received yet. So we have 300 units that are not sellable and are "lost."

We contacted Amazon and they gave a bs answer and just said keep waiting basically. How long do I have to wait before they will consider reimbursing for the loss? The first shipment of 150 has been lost for 2 months exactly. What should I do?

I can't keep waiting months for them to check inventory into their system. I'm tempted to send another smaller 50 unit shipment in, as that seemed to be checked into inventory quickly, where these 150 unit shipments are taking forever or getting lost!

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