Being on the Do Not Call list doesn't stop any calls or immunize you against all unwanted calls. It is not a call blocking service. A call blocking device is what you need to stop unwanted callers.
So? It's just a list. It is Required to be purchased by legitimate and registered with the FTC, Telemarketers.
"The List" doesn't do anything else. Not a call blocker and doesn't immunize you against any calls.