Unsolicited phone calls

We are on the National Do Not Call list and still are getting the same pre recorded message.  We HAVE no debt nor would we go to someone like this if we did.  I press the number to be connected to a live person, and someone with a foreign accent comes on.  I tell them that we are on the Do Not Call list and they are violating federal law and they hang up on me.  I've pressed the number they give that allows you to opt out of receiving their calls but that doesn't do any good either.

These people need to be completely shut down.  They are a scam of the lowest rank.