A quick update:
This morning a got an email from DT asking me to fill out a customer survey. I was honest and politely let them know I didn't appreciate being told one thing and finding out someone dropped the ball on getting the tires ordered. A couple hours later I get a call from the store manager. He apologizes repeatedly for the oversight; I tell him thanks and not to worry about it. He insisted on "making it right" and proceeded to tell me he would refund the purchase price of two of my tires. I tried to tell him that wasn't necessary but the manager said it was in order to keep my business and recommendation.
Needless to say, DT has earned my future tire purchases. I didn't think customer service like that existed anymore.