Anyone else having issues getting refund for lost shipment ?

I shipped 3 boxes early november 2024 which has been delivered but they act like of the 3rd box was empty

The box number 3 had 100 units of X0048DW9LJ inside as per the web form. 

Shipped by UPS 1Z10074A2040730446 Nov 07, 2024 10:27:17 AM - Caledon ON CA - Package delivered.

Box #3 FBA18KQX9X6DU000003 the weight match.

Then they asked me to provide invoice which I did.

Since then , all I get is lies of being contacted within 24 hours or that they still work on the case

"As much as I would like to resolve this now for you, this is out of my expertise, but we have a separate department that is more equipped in resolving this matter. As the team is not available on chat, expect a reply from them via email within the next 24 hours"

That 24 hours has been going on since Nov.30....

Any suggestions on what to do ? It's getting terrible.