I as well never answer numbers I don't know. Just put them in your reject list. Once I do that it hangs up on them. Another service I used tells them the number has been disconnected. Find me, sue me, get in line.
Called several times without leaving a message. I'm guessing it's some sort of unwanted garbage but not sure of the type and not interested in finding out.
They call everyday..very annoying. ..I do not have anything in collection...put the number in reject list...next ..I will forward the number to my attorney and file for harrasment.