AT&T Calypso phone unlock failing - doesn't like the IMEI
I am using the Device Unlock app (which came on the phone) to unlock an AT&T Calypso U318AA that was sent to me by AT&T a year ago to replace a phone that would no longer work after the network changes to take place in February '22. I have tried numerous times on different days, and it does not recognize the IMEI as an AT&T IMEI. "Looks like the IMEI number you entered doesn’t match an AT&T device. Try entering it again. Dial *#06# on your mobile phone to make sure you have the right IMEI." I get the same message when I try to unlock it on the AT&T website.
I have another Calypso phone which was sent at the same time to replace a different phone (different family members) and it unlocked using the Device Unlock app about 6 months ago. How can the IMEI be wrong when these two phones seem to be identical? What can I do to get this phone unlocked?
How can I get the IMEI added into the IMEI Unlock Database? The phone is in active use on AT&T Wireless and meets all the unlock qualifications.