called AT&T prior to ordering from RS and got confirmation that they would switch my plan back. Since they activated my new phone already (before it was even shipped) I called AT&T to get the rate plan switched back. After spending 40 minutes on the phone with a very upbeat girl with a southern accent named Christy, I was told they had to open a ticket and I would get a response by May 18th. But she also mentioned that any overages I incurred because of the wait would get refunded back to me.
So.. Yay for that. Oh, and I also got confirmation that my order was shipped and a tracking number was generated. So let's just hope that in 24 hours this craziness will be done with for everyone!