We have some shared line appearances on 4 phones. We have a new phone number we want pointed at Ext 101. I take the shared line appearances of Ext 101 off of the other three phones Ext 100,103 and 105. When the phone number of 499-1251 is dialed it still rings all 4 phones. I have setup Ext 101 as private not shared line appearance. What am I doing wrong?