my iphone wont get service it just says "searching" for days

i have a white iphone 4s 16 gb and i was out and i couldnt charge it, my phone died and once i got home i plugged it in and all it said was searching, i turned it off and took the sim card out because i thought something with telus was wrong but i turned it back on and it didnt work so over night i took the sim card out and turned it off and left it over night and i turned it on in the morning but it didnt work. its been atleast 4 days that its said searching and in settings its supposed to say carrier but it doesnt