The reality is that awards across partners are often a pain in the butt in these circumstances. There's really not much else you can do as the only actual recourse you have is to get a fee-free refund of the miles. There's really no "leg to stand on" in trying to get someone to do something, unfortunately.

When we couldn't get the LAN connection we wanted on a LIM-CUZ connection, we just kept the original (less convenient) booking and went on the day of the flight and simply switched to the earlier flight. They didn't have to let us, but they did. (Of course, this story goes downhill from there...but that's a different saga )

Cheers.