You can get the unlock code from unlock-zone simply at your laptop or pc you can get this its so simple
How Do I Unlock A Blackberry Curve?
I just Unlocked my BlackBerry Curve from UnlockGenie.com
I got my code instantly and I unlocked my phone without any trouble. 
But the codes are not free....Before I tried many free codes I got from some websites but none of them worked. According to my opinion you should go for good websites like unlockgenie.com and get a genuine code by paying a few dollars.
Why pay for your Unlock Code when you can get one for FREE at www.freemyblackberry.com