I currently (7-2019) have 2 Blackberry Z10 phones using  Verizon.  I went to add a line and wanting to use another z10 but am unable to do so according to the website.  I called c.s. and samething because of the new network..WHY ???  Is there a way to make it happen?  I don't want to learn a new phone and operating system for my youngest child.