I went away for two weeks for work.  Came back and I purchased a new Xbox so I can play when I’m at work. But for some reason I am no longer a master and someone else is. 
 

 How is this possible and how do I get my guild back ?

Unfortunately if you haven't logged on for 15 days it makes it to where an officer can take over and start running the guild. This mechanic is made in order to keep guilds running in the event of a GM quitting without informing his officers. The only advice I can offer is to contact the player and request to have guild permissions back. 

CM Valtarra