I called up Opal customer care today and my god, their menu is a headache to navigate through. Here's how you talk to a human:
Call 13 67 25 (13 OPAL)
Press 9
Press 7
Enter your Opal card number
Enter your pin number (not the one on the card)
press 0
Hopefully this helps someone who calls up to ask a question or needs to get their balance adjusted.
This is good mate. I had to go through the pain today morning, twice!
Will use this in future, thanks.