Depends on who's your provider and if they are having issue with the mainframe. Plus your relevant location to a hot spot/wifi or cell signal could be limited/restricted. Check to see if yoru wifi signal is active as well as your cell signal located at the top of your smarty phone within a drop down tool tray.
As a reminder if you're located near a hot spot or have access to wifi, you may need to reset the wifi signal as to be allowed to use this service. If you're within a wifi signal area but do not have access to the system, you will need to approach whom ever is the signals host and request a wifi signal code as to be allowed access to their services.