I've been getting calls too. A few yesterday and a few today. Left a minute long voicemail of what sounds like a TV playing in the background talking about kilometers or something.
When I saw the 555 prefix, I knew it was fraud, so I just sent the call to the FAX machine! LOL! I love doin' that! Give 'em a big squeal in the ear and that'll make 'em mad as Hell, at least! "Go ahead and call me back!", I think... :-D
Two things. No one sits there dialing phone numbers. That went out decades ago. So the only thing that will hear that squeal is their computer and it don't really care one way or the other. Further, there are some legitimate 555 numbers. Look it up.