Who called from 4693429122

A hang up call, left no message.

phone was ringing as I came into work, caller left no message

someone is tracing ur call and finding out where ur located.

Calls multiple times, does not leave a message.

I keep getting calls from this number; I don't recogize it therefore I do not answer it; the person calling leaves no message.  I just called the number from my work phone & it's a collection agency.  I told them that they left me no message & she replied that they do not have to leave messages.

Now when does a collection agency call to collect a debt & leave no message when the person doesn't answer?