Originally Posted by
Flying Machine
SDC on UA is typically permitted on UA metal only. The best angle for a change would be minimum connection time in my opinion. Best of luck
Agreed on playing the MCT card.
The MCT should appear on Amadeus/Sabre when they go through your booking. I don't know how long it is in the case of an EZE-AEP transfer, but 2 hours seems impossible, particularly when coming in from an international flight and having to go through customs and immigration.
Whatever you have to do, do it before getting to AEP. There is no Star Alliance, let alone UA, representative at AEP, and AR does not have any agreements with United, so AR people will probably be quite clueless. Your last shot could be the UA desk at EZE, but still, I would try to sort everything out before leaving home.