If you are within the 24 hour cancellation period, you could cancel them and rebook...but you aren't guaranteed to get the same price.

He can either keep the BPs and send them to the SMSC after the fact or you can call again. If it is a common sense difference where any layperson could see that the two were the same, he should have a problem.

Otherwise, I'd say call Delta. And I say this knowing that you already called. It can be done. You might have to ask for a supervisor but if it is a common sense difference, it CAN be done. I know from experience.