you might have registered on the Do Not Call list, but that doesn't mean you are immune. you may need to re read the directions on that site. you must enter each number that comes to your phone and log it in as a number that must not call you. takes supposedly 31 days before that company must comply, or get penalized [ LOL ]. But many companies use multiple numbers, automated 'robo call' systems, or even the humans use a variety of numbers, especially the flunkies working for collection agencies.
Got a call from this number couple hours ago. I didn't pick up and it didn't leave a message. After that I got another call from 571-362-0439. Same thing happened.