Our Yammer implementation has two different networks

Last year we migrated from our exchange server to Office 365. I've been playing around with Yammer and would like to roll it out. I noticed that some of the older accounts that were migrated to Office 365 using Skykick, are using abc network. But all of my new users that are created in yammer are all part of xyz network. There are literally two URLs for these networks like:

https://www.yammer.com/abc/#/home
https://www.yammer.com/xyz/#/home

The activation emails also go out to the users based on the network they are in. HOw do I get all users into one network? I am the admin but I can only see the network I am in which is abc. I can't even see the xyz network to join the two together? Also I'd like the confirmation email to be for the right network.