How to unlock iphone network?

Ok, so i've just got a contract with 3 and i'm currently on EE, i got the sim card this morning with 3 and put it into my iphone, To then realise my iphone was locked to EE, I Got told there were tweaks in cydia so i jailbroken my iphone and i'm not sure how to unlock my iphone for free, because all i can find is scams! Any help will be brilliant thanks

Unlocking and jailbreaking are not the same thing. Jailbreak is to root or get access to the iOS that Apple never intended. Unlocking is where the phone's programming that was set to one specific carrier is now open to be used by any carrier of your choosing. You need it unlocked. Bottom line, can't guarantee that it will be free. Might cost a few bucks. Best luck.

Before doing anything else.
Call EE and ask how much an unlock code would be.