Wonder if this is part of side effects of trying to consolidate AA and US reservation system, such as meal pre-order is temporary not available online and will be back on November.
What is the chance where you actually decide to pay $15 fee for another receipt, then the new receipt you got still only show the fare difference only and no change fee?
So, after mentioning that the original receipt was incomplete and the agent is still saying to pay $15 to get another receipt?