Call all the time and never leave message.

Called asking for information that I did not give out. Asking names of managers etc...Stated they need assistance with .NET. (Call Microsoft for .NET questions, I don't work for them).

This is the outbound number for the Lassen group, a recruiting agency (i'm in IT). I contacted them initially when i was starting my job search, so no spam/cold-calling on their part in my case.