Weird calls when packages delivered

I’ve had this happen multiple times now and I’m trying to figure out why. I order a whatever from amazon. My apartment building has a place where drivers deliver a package and you can pick it up later (locker storage).

After it’s delivered, I’ll get a call from what appears to be a valid number. I answer, and it is what appears to be a real person mumbling something in a language I don’t understand or recognize. I speak three languages (English, Spanish, Japanese) and recognize many more. This isn’t any of them. They seem to be wanting me to say something, but after a few short sentences they hang up. I already know the package is there because I got an email/text/whatever, and there’s never anything wrong with the package, it’s just normal, exactly what I bought, no problems.

So what is this? I know my building managers, and it’s definitely none of them. Is this some kind of shitty step in the fulfillment process that drivers have to do now? To mumble incoherently that your package is here? Am I a pawn in a greater scheme? Am I helping to finally summon Cthulhu? IIRC it’s been going on for a few months now. I rarely order things so it took a while for me to pick up on the change.

Thanks fellows, and I’m happy about the earlier sunsettings too.

Edit: To clarify, the calls are never in an angry tone and never feeling threatening. It’s like you would make completing a business transaction, very normal, and then they suddenly drop off. I’m just trying to find out what’s going on.

Edit2: Ok I thought this might be a simple dumb thing I didn’t know but I guess not. I’ll keep track of numbers and dates if it happens again, recordings if I can figure that out. Thanks everyone.