I learned this secret from my sister. After trying everything to stop this kind of calls, this is what my sister said to do. So far it's worked, but they seem to come back from a different phone number. I used to get this same calls from area code 480, that stopped, but then I kept getting the same thing from area code 520 so I keep doing the same thing. Answer, don't saY A WORD AND PRESS THE POUND KEY OVER AND OVER.
uNTIL i GET THE SAME CALLS i WILL KEEP DOING "ANSWER, DON'T SAY ANYTHING, AND PRESS THE POUND KEY OVER AND OVER AND HANG UP!