They call every other day. I finally heard the recorded message. Like others have mentioned, they are offering security services. At the end of the message, they tell you to press 1 to speak with a rep, 2 to be removed.
I have hit 2 twice. I have also blocked the phone number locally on my phone in addition to in my Verizon account.
The number still gets through...which is a clear indication that the 602 number is just spoofed...that is not the true phone number that is calling you.