A lot of these type of calls are for bridging,,they are from company's sending data across to another state,,,don't answer and turn off your answering machines,,,if you or your answering machine don't answer they can't connect and they have to use another #,,lets keep them busy trying to find another #,,that is why the phone company has given you a portable #,,,also called line splitting,,,,years ago it was called a party line,,,,we are being scamed by the phone company's,,,you can do a search of all of this info on your computer,
look up line splitting and bridging,,,have you ever called one of these #'s back and it said this line or # doesn't recieve incoming calls,,,think about it,,,,