HEY… 
SIX DAYS AGO I LOST MY GALAXY S4 WITH ANTITHEFT ON IT… OBVIOUSLY I CALLED POLICE AND MY COMPANY WHO CANCELLED MY NUMBER, SO I SUPPOSED IT CANNOT RECEIVE SMS COMMANDS, AND ACTUALLY CANNOT USE 3G WITH MY SIM CARD, WHEN I INSTALLED ANTI-THEF I PUT MY OTHER MOBILE NUMBER AS FRIEND BUT I HAVENT RECEIVE ANY SIM CARD CHANGE SMS; IN THE WEB PAGE IT SAYS SECURED BUT THE LAST CONNECTION WAS THE DAY I LOST IT, AND EVERYTIME I TRY TO TURN ON STEALTH MODE IT SAYS COMMAND TIME OUT, AS WITH ALL THE OTHER COMMANDS… WHAT IS HAPPENING? WHY I CANNOT LOCATE IT WITH SMS NOR WEB COMMANDS? I USE THE SAME PIN THAT I ALWAYS USED TO UNLOCK MY PROTECTED APPS… ITS THE SAME ONE THAT I HAVE TO USE TO SMS COMMANDS? IS THERE A WAY TO RETRIEVE MY PIN? HELP PLEASE
Hello,
most likely your phone was turned off or ran out of battery. I’m afraid you can only wait until someone recharges it/switches it on.
good luck,
Werner