This is a "one-ring" (or two) scam to get people to call them back. Once you do that, your phone number gets "on the list" and you will then be tossed around any number of scam calls. Don't call back. If they call again, don't answer.

If it gets too annoying (it will stop eventually) look into a call blocker, which will allow you to punch in the number once and be done with call from there.