Missed calls are rare if setup is done correctly. This is also assuming your KWs and campaigns are driving people that want to make call. A missed call is either an error in your phone number/Kallzu setup (refer to training) or it's a targeting issue (if setup is working correctly). From the information you gave me (1 very limited screenshot), I have no way of knowing exactly where your problem is, but I can at least give the only two possibilities of where the problem is.