No one can resolve the issue

My Samsung was booked in to be fixed. The software was reloaded. Now the always on shortcut on my phone doesn't work anymore. I've phoned many times to have it fixed but no one seems to know how. The shortcut tells me the device was not registered before, but when I enter my credentials to register it gives an error every time. Call center doesn't know how to resolve it also. What am I to do?