Need help with supposedly unlocked Iphone 3GS

[infestissumam]

Bear with me here, as I am an Android user trying to figure out how to use this iPhone I got for free from a guy I met. The guy told me that the iphone was carrier unlocked for At&T, straight talk, t-mobile, all of those. I got my AT&T sim card and popped it in, and the phone read the sim card, but didn't have service. What I mean by that is when I put the sim card in, it recognized it had a sim in it, but next to the service bars it did not say at&t. When I tried to make calls it would just say call failed immediately. i am assuming it is set up for another carrier that isn't at&t, but I have no idea how to check it or how to change it. It is an iPhone 3GS that is running 4.1 version software and I am assuming it is jailbroken because it has cydia installed.


Any and all help would be much appreciated. Thanks in advance.

[bftiedt]

Hey man I do factory unlocks and we offer a service that can find what carrier the iphone is for you. If you need help or need me to explain to you email me [email protected]

[GnatGoSplat]

Just enter your IMEI into this site and it'll tell you for free.
iPhoneIMEI.info :: Free iPhone IMEI Checker
There are a bunch of others, all free, but that was the 1st one in my browser history.