You've tried to unlock this device too many times. Wait 30 days and then submit a new request

Thanks for reaching out @bestdae21, we are happy to help get your device unlocked!

As @dwill05 suggested, it would be helpful if you could tell us where and when you purchased the phone as only the original owner can unlock the phone. 

In the meantime, it would be helpful to make sure you meet all the requirements for unlocking your phone by verifying that your phone:

• Is an AT&T phone or device and isn’t active on another AT&T account.
• Was paid in full when you bought it (not on an installment plan). You don’t have to wait 60 days to unlock it.
• Has a paid-off installment plan.
  • Paid through your monthly bill: Submit your unlock request at the start of your next bill period.
  • Paid off early: The wireless number assigned to the device must be active for at least 60 days. Wait 48 hours after you make your final payment to submit your unlock request.
• Doesn’t have a past-due account balance. Make a payment to bring your account current. It will take 24 hours for your payment to post. 
• Hasn’t been reported as lost, stolen, or involved with fraud.
• Is an AT&T PREPAID^SM phone that has had paid service for at least six months. Check your device for an unlock app and make sure it has the most recent version of the app. Don’t see the app? Submit an unlock request online.

Please let us know if this helps.

Joseph, AT&T Community Specialist

Where and when did you buy the phone?  If you just bought the phone from a second hand source, the previous owner may have tried (and likely failed) to unlock it on their own.