Submit a ticket to Nitrado. Include all the details. But if you can connect and others cant, more than likely its a client issue. Or if you have a ban section, check that.
I do not understand what you mean. Ban players is not available in the admin area of the DayZ game on the Xbox. Did i think you know it. By the way, there is some information about expanding the capabilities of the Administrator in future? Ban list, Administrator Teleport, Setting spawn loot.