I have been getting this call for over a week now also...I never answer a call in my cell phone if I don't recognize the number. I am on the do not call list as well, don't understand how they can still harass people all the time. Eventually they will give up calling though, I will never answer!
Call the number back, you will be prompted to put in your phone number, and then confirm it by pressing 1. They will confirm and tell you it will be removed within 2 business days.