I called again and tried a few things:

1. asked them to push open a Milesaver availability on their own planes. They said they can't.
2. Asked them to cancel my return leg from MUC->ORD. They said they can't.

pretty much they cannot do anything that I cannot do myself online. It was a waste of time. I'm pretty upset about this.

Do you guys have any other idea? Or should I keep calling until I get lucky with a rep that would help me out.

Thanks!