AT&T Note II i317 blacklisted/blocked IMEI?

Okay, I have a Galaxy Note II i317, it used to be my mother's until she had a very tiny crack across the screen to which she got a new Note II at the time. I recently decided to try and use the phone with Straight Talk....
A few things I've done/tried...
Putting the Straight Talk SIM card into the phone, reads No SIM/Emergency Calls Only
Changed the Firmware back to 4.1.1 from 4.1.2 and tried to unlock the phone using the unlock code...unsuccessful
Tried Rooting the phone and using TWRP to change the Baseband... no avail...

I guess the main question I have is if I can even do anything at all to use the phone, or would the IMEI be blocked because of the replacement phone?

Any and all help would be appreciated!!!

Thanks!!![/SIZE]