Items lost in FBA after received, but Amazon seller support replied no item lost.

We delivered 525+129=654 units items of two ASINs to FBA after Sept 1st 2023 and they are all received in record. And these two ASINs are out of stock now, but all the orders of these two ASINs in our store is 256 units (only a few orders buying 2 or 3 units) from Sept 1st till today.

I contacted the seller support, they just replied that they check the data in their system and didnot find out any missing items. This is really ridiculous. I sent them all the proof and shipment records that can prove 654 units of item we delivered to FBA and we only have 256 buyer orders. This can clealy prove that more than 400 units are missing in FBA after received. But they only trust the wrong data in their system and refuse to verify how many items we delivered to Amazon warehouse and how many items have been sold out from Sept 1st 2023 to today.

May I ask Amazon, we delivered 654 units to FBA warehouse and we only 256 buyer orders (only a few orders buying 2 or 3 units) and they are out of stock now, it is resonable?

It is a very simple math question. And you can easily verify the data in your system is wrong if you guys spend one minute to verify how many items received and how many items sold during Sept 1st 2023 to Dec 6th 2023.

I have no idea why this has happened. We did lost a lot items in FBA warehouse, but the data in your system shows no items are missing.

I am highly appreciated if you could give some advice to resolve the whole issue. Thank you.