Im assuming its the scammers as work again, as we are receiving ghost calls about every three days or so between the hours of 5pm - 7pm approx. The call is answered and there no one there, I shouted down the line and nothingm, left it on speakerphone and call was disconnected after about 20 seconds.
Im assuming its similar to this scam:
http://money-watch.co.uk/6504/076-phone-number-scam
Also had the pc fix scammers call the other day, I palyed dumb and took them on a ride for good half hour or so.