I've been getting these call for several years.
This what I've found to be pretty effective.
I made a list of spam callers phone numbers and when one of them call, I answer with
AN INDIAN ACCENT AND SAY HELLO, HELLO, HELLO, AND I DO NOT IN GAGE IN CONVERSATION WITH THEM. This drives them crazy and they hang up.
Mission accomplished! Then they put me on their DO NOT CALL LIST. !!!! I win.
Now, those call have dropped off a lot.
It works for me, Try it You'll like the results.
9/6/13
If you are getting calls from these people, they are bill collectors. I owr money on a car i bought and the company that calls me from this number is Westlake Financial based in california. Idk if they are the only company that calls from this number or not. Hope thats helps everyone.