We get these calls several times a day, if we don't get to them on time or do not answer it they do not leave a messege.  If we do answer it, most of the time there is a recorded messege saying to please stay on the line for an important call.  Other times when answered I can hear typing.... And i say Hello repeatedly, but noone says anything, so I hang up.  If it were not for the fact, that I live with someone that is hearing sensitive I would use a whistle when they call in.  

I wish they would stop.