I was promised a $200 reward card for starting service. I then entered the code on the reward site, and it states "reward disqualified".

Dear Wendy Swan,

Congratulations! Your recent purchase of AT&T service
qualifies you for a AT&T Visa® Reward Card*.

It’s easy and quick to claim your reward online.
Just follow these steps:

I did so, and the reward has been "disqualified" FOR NO REASON.  I will PROMPTLY disconnect service as soon as the competing service can connect my WIFI just based on principle.