I've been getting a lot of spam calls from alleged European numbes (and the scammers appear to be speaking Spanish when I overhear them) since my son foolishly entered my number into a website to "win some Robux!" (a very teachable moment about Internet scams) - they list an overseas premium number as the calling number, then hang up before you can answer, in the hope that you'll return the call and end up paying 20 euros for the privilege.

I made a deliberate effort to answer such calls on the first ring, thus costing them money by connecting the call, and after two weeks of that the calls stopped.