lost or stolen iphone 4s

hi all

i lost my iphone 4s today

when i came home i called local police and reported it lost or stolen they asked me imei number which i found it on iphone box.

i still dnt know how they will find it with this number tho

i also tried i cloud using find my phone but it shows offline i think i forget to able find my phone on device

dnt know what to do?

i am really upset still paying contract next 18 months

its still under warranty but no insurance which means warranty doesnt cover lost or stolen

is any other ways that i can find it ?

please any advice

thanks

musty