Wow that was painful. Was on the phone with them for over 40 minutes, but I got the unlock code! They were actually helpful and friendly. There's a problem though... they don't have directions for unlocking the Lumia 900, only the codes. Does anyone know how exactly to about doing this? I need to be careful to do this right as you only get a limited number of tries.
*EDIT: So far the only method I've found to enter the unlock code is to enter a different (non AT&T/related MVNO) sim and power on. I don't have one handy though. I'll get one from someone else if necessary but does anyone know any other method of entering in the unlock code? Thanks.