called four times within three days and left a silent voicemail. wtf?

seems to call twice every other day on cell ... no answer on other end

I got a call from this number asking for Matthew, I said Matthew isn't with me right now, he is my son.  The guy on the phone said "you're Matthew's Mom?" I said, "yes, what is this in regards to" and the guy said "that is for your son Matthew's information only" and I said,"my son is 8 years old" and he said "it's for your 8 year old son's information only". I told him that there was something seriously wrong about this and he said he would get his manager but no one ever came back on the line.

Calling and hanging up. Stop calling.

called my cell phone twice today and left no message.