Hi and Welcome. My Name is ***** ***** I look forward to assisting you today with your question.
What is the model and make of your phone ?
If you don't remember the passcode, then we need to factory reset it. Please stay online. I will send you instructions in here.,
There are no manufacturer instructions available to reset it, so we have try some hidden method to reset it. Remember this will delete everything from the phone. This is your only way.
Turn off the phone. Then hold down Volume Up and Power button at the same time for 10 seconds and does it bring any menu ?
Can you try Volume down and Power for 20 seconds after it is turned on?
There are no official instructions available for this model to reset. I will open this question to other experts in here. If they have any idea they will get back you.
Actually none of the experts in here will be able to unlock it because it has to be AT&T who should unlock it for you. Have you tried contacting AT&T to unlock and see if it eligible for unlock ?
See here --> http://www.att.com/esupport/article.html#!/wireless/KM1008728
Can you try these key combination on your Pantech ?
Turn off the phone completely. Then hold down Volume down and Power button at the same until a reset menu appears ? If it boot it back to lock screen, then release the buttons.
Turn it off. Then hold down Volume Up, Volume Down and Power for several seconds and does it boot into any menu ?
Or did you try the default combinations like 0000,1234, 1122 ?
Then you have to go through third party unlock services to get it unlocked or get the unlock code. I'm not sure if AT&T unlock it from their side.
There are many online unlock sites available. Following are some
The problem is you have to pay for the unlock code. I'm afraid your phone is backlisted and the unlock might not work.
Re Pantech, did you try these steps ?
May be he can call AT&T and ask them to withdraw the 'lost complaint' or ask him to talk to AT&T directly to get it unlocked ?