Trying to add GIG-GRU to an award ticket
Resurrecting this thread, I am trying to add the UA GIG-GRU add-on flight to an all-UA metal award booked via CO (current routing is GRU-ORD-DCA in C). I got a helpful agent at CO who told me it couldn't be done...even after checking with both the "integration desk," and calling UA. Their basic argument is that since UA's GIG-GRU can't be sold independently, it cannot be added independently even to UA flights to which it is an otherwise legal connecting flight. She told me the only way to book this would be to cancel my existing award and then attempt to book it again with the GIG-GRU leg as part of the original booking. I'm not willing to do this, because it is right around New Year's and I doubt that the seat will be returned to award inventory.
By way of background, UA is showing award availability on the GIG-GRU flight segment via expert mode. Because this is around New Year's, there is no TAM availability to attempt to tack on.
Has anyone ever been successful in adding the UA GIG-GRU to an existing award?
(Oh, and before anyone says it, I know I should have booked this with UA instead of CO to perhaps increase my chances of being successful in this, but what's done is done.)