Samsung galaxy s3 help/questions

[Kelly Mitchell2]

Ok guys this question may or may not have been already asked but being new to this stuff i thought I would just bite the bullet and ask straight out, long story short I bought a galaxy s3 the other day off gumtree and a few days later bought a SIM card only to find that the phone was blocked by the carrier due to it being either lost or stolen due to not getting any details off the guy I bought it off and meeting him at a car park in maccas I am now stuck with this phone that is useless to me, I have been watching these movies on YouTube about 'rooting' the device, like jail breaking? And I was wandering if there was an app or something like that that I can install to make use of the phone?
Thanks in advance

 

[Voliam]

The IMEI number identifies the phone on a network, and cannot be changed by rooting the phone.

Sent from my SAMSUNG-SGH-I747 using Android Central Forums

 

[Kelly Mitchell2]

Therefore it's pretty much useless?