I made an appointment for tomorrow at an ATT store a few days ago to do the in person trade in. I don't trust the automatic system.
This link makes the process a lot clearer, though.
https://www.att.com/esupport/articl...w-3LQ27nV1_OAo9HvLvHhaKg#!/wireless/KM1123971
AHA Now it all seems more clear and there IS a promotion code for the trade-in website: FALL2016TRADE