What happens now is that legit companies are not calling anymore. It's only scammers. What they do is use a PBX or Voice Over IP system where they can set the caller ID themselves. When they call someone, they create a new number (sometimes daily, sometimes per call) that appears to be in your area code. So you report them to the Do Not Call registry, but the number is bogus, so the Feds have no way of knowing who actually called you or who to fine. If you ask who the company is on a call they'll either hang up on you or give a generic name like "Carpet Cleaners".