Can AT&T still unlock my iPhone?

I just got an iPhone 4 yesterday and I want to unlock it so I can use it on t-mobile. I'm gonna call AT&T and ask them to unlock my iPhone but the thing is that I'm not an AT&T customer, I use to be. I left AT&T to join T-Mobile 2 months ago since it was much cheaper. Here's my question. Last month I called them to unlock a AT&T prepaid phone. They told that I would get an email a few days later. I got the email saying that the phone could not be unlocked, so I basically got rejected. Now since I just got an iPhone, do you think they will reject me again or will they unlock it? I know AT&T has this policy saying that non AT&T customers can only unlock 1 phone a year

You have to take it to Apple to unlock it. My friend took it to apple because she had Sprint before sprint had iPhones and she took it took apple. But apple has for over night:/

Hi, it is possible to use the following official carrier granted unlock for iPhone 4 (but only if the phone is not blacklisted or associated with an AT&T account in debt): http://www.fastgsm.com/en/apple/apple/iphone-4/unlock

Just call them again.

Go to unlockatt.com they unlock them no matter what for cheap