SEARCHING SIGNAL

Good Day;

i'm Mr. Chito Duga Duga, i am a I phone 5S user and i am here in SAUDI ARABIA. its been 2 days already that my phone is keep on SEARCHING for signal. my IOS is 8.1.3 just updated it.

i done reset network, erase all settings, change Carrier from automatic to manual set up. i remove the Sim and returning it and do restarting every time i change the settings. but all i did still not working, still my phone is keep on SEARCHING the signal for my carrier Sim. i can't send and receive call/messages. please help me to solve or fix this problem...what should i do to fix the signal of my i phone 5s???

thank you and God Bless

Chito