Has anyone successfully had CS perform a missing package trace?

I purchased my girlfriend a fairly expensive skincare set and it was marked delivered by UPS today without actually being dropped off. I was by the door when the package “arrived” and they clearly never delivered it.

Regardless, I tried contacting UPS to trace the package, and they said the seller had to engage it. After what I thought was a really great first interaction where the agent offered a refund or replacement, every followup was terse and effectively said that Sephora couldn’t assist with anything, whether a replacement or refund (which I never asked for) or contacting the shipper. I really don’t have the funds to replace this and really just want them to report the package missing so I can get a response from UPS.

Thanks either way.