I purchased my phone through Sprint a couple years ago and have recently needed to switch providers to Mint Mobile. I've spoken with Sprint multiple times and they assure me the phone has been unlocked but when I put the new SIM in the phone displays a message of "Invalid SIM" and I do not have any options to modify/add APN settings.
Doing some research into this, it looks like a lot of people have run into similar problems and it looks like it's probably related to an update - software version LS992ZVF.
After spending most of last Saturday driving to multiple Sprint stores and calling Sprint multiple times to try and get help, being hung up on _twice_ by Sprint, I was told my phone would be unlocked and to expect an email Tuesday or Wednesday to confirm. I received an email tonight(Tuesday) saying my phone is unlocked... It is not, other provider's SIMs do not work, and judging by the problems others have had, I don't expect a simple unlock will do the trick. The email 'confirming' the unlock was sent from firstname.lastname@example.org so there is no way to follow up. Hence this post.
I've been a customer for about 15 years. I do not have another phone or service lined up, but at this point I will not be going back to Sprint.
was your phone turned on with the Sprint sim card in it while connected to WIFI when they said you would get a notification that it is unlocked?
If the system says that the phone is unlocked and it's still reading locked through the phone, then it didn't receive the unlock signal. To receive the unlock signal, the phone needs to have a Sprint SIM in it, it needs to be powered on, and connected to WiFi. Was the phone on your Sprint account?