Finally got a call back from a "customer resolution expert" for the complaint I submitted via the website form last week (after repeatedly missing their call over the last few days for various reasons--my fault, but they somehow managed to pick the absolute worst times to call -- including while I was on my way through security at SYD yesterday afternoon).
She proposed moving me up from the $49 plan onto the $59 plan for reasons I didn't understand given it doesn't include roaming either, and applying a $15 monthly discount. So a net $5 discount, which is a bit derisory given others on here have been offered $20.
I'll be porting out tomorrow.