When I answered, there was no one there. When I called the number back it answered with a recorded message about WCA Services and that "we value your participation". Not sure who it is.
If you call the number back and listen through the first minute of the recording it tells you if you want to take your # off the list to press a number and then you are asked to enter the number you want removed from their calling list. I did this and have not had any more calls from that number.