Sorry to hear about the bad experience.
Last week, I was in the middle of a MR. Did LAX-SEA-DFW. The LAX-SEA was delayed causing to miss my DFW flight. I didn't want to take the redeye. Agent rebooked me on to AA within 5 minutes. The rebooking didn't go as smoothly (APIS information never got stored and had to check-in at the gate). But it was pretty painless getting rebooked on to OAL. After the initial AA flight got sorted, I changed my flight to a later AA flight after seeing I could clear the upgrade list. So despite the technical errors, it was VERY painless getting rebooked onto OAL. Having no bags did help of course.