Just remember cordless phones need power to work - you need a corded phone for power outages.

I get these calls on my cell phone, which is also on the Do Not Call list.

THESE ARE SCAMMERS!  HAVE NO DEALINGS WITH THEM.  federal trade commission wants to know about them.  report them.

I'm having the same problem with blocking the numbers.  It seems they have a new number as soon as I block one.  They are working in groups with different scams.  Google and some others make it too easy for other countries to get American phone numbers.  That is one place perhaps the law could crack down.  Nigerians and people from Ghana are pretending to be from the US with US phone numbers. (just for example and problems I've discovered)

Block one and another one calls  I get at least one or two calls a day, having blocked the last number that called.