The phone says to use iTunes, but no account.
You don't need an iTunes account, you just need to plug it into to your computer with iTunes software installed.
Using SAM tool,you can do it -
If this doesn't works,then the reason could be that possibly,Apple might had patched it.
Unfortunately you're unable to unlock your device without the assistance of iTunes. Unlocking the device through iTunes is the last vital step to unlocking your device as it does need the approval of Apple.
Is there any particular reason in which you want to unlock your device without the iTunes step?
Are you unable to connect to iTunes to complete the process?
you need to either connect to itunes or go into an apple store because your device does need the approval of Apple