Who called from 9712201781

I also noticed 5 diff. numbers I did not recognize calling and not leaving a message today, I KNOW its RACHEL CARD SERVICE that have been harassing me for years,  I even said I dont call I dont have credit cards at the beginning, yet the calls continued from other numbers.  SO today I thought I would call back ALL the numbers and blow a VERY loud whistle- but every single number was a DISCONNECTED number.    How do they use these numbers if they are not even registered numbers?  Im calling the FTC- speaking so someone LIVE!

just got a call - thur, 12/20 2:28 pm central.   no msg

I'm going to try the silent ring tone! I keep adding these numbers to my block list but they call from a different number a week later. I wonder if I can assign silent ringtones to any number not on my contact list?

A holes called but no message.  Glad to see what it was about and not to answer or call back....

I am on the don't call registry.  How is it they can call me on my private cell phone??  Isn't it enough they bother me at home too??