Many "family" offers aren't available to businesses. How many businesses would need to (or want to) finance a bevy of $1K phones?
Just wanted to pop in here one more time. We have a thread about a similar issue where a user found out that it was a "Sim card lock" that was put on the account. I am not sure if this is the case here but it is worth a shot to look into.
Here is the thread Re: Apple iPhone Upgrade Program T-Mobile PIN Code Issues
Please do contact us when you have a moment so we can look into this as the possible cause.