I decided to order a pack of 4 Airtags directly from Apple as I wanted them engraved.
I was at home the day the brown, cardboard box was delivered. I signed for the package which I took inside and opened immediately. The box was a real pain to open as it had been very heavily sellotaped but when I opened it, it was empty! The package did not appear to me to have been opened and re sealed.
Got on to Apple who asked for photos of the box etc but they couldn't really grasp that the box was empty.
Long story short, the matter was eventually escalated to management (by them) because they wanted both a stat dec plus they wanted me to report them as stolen to the police which I said I couldn't do as they weren't technically stolen from me (police station confirmed this). So, after a lot of debate, Apple accepted just a stat dec witnessed by the duty police officer.
When I suggested maybe they had never been packed, Apple said the international tracking showed the box as having the correct weight the whole time, so no idea where they went "missing".
Apple follow up was good and I received my new, engraved Airtags a couple of weeks later which I arranged to collect from the Post Office and opened in front of the staff.
I do wonder where the originals, with my family's initials and emojiis went. I was told that apparently someone tech savvy enough can use them for themselves and Apple can't trace them.