EnergyAustralia have already emailed the amended bill after cocking up the first one. Hopefully their customer service is that effective for any future problems we might have.
I'm still not 100% sure about how they adjust their prices for the blocks, which makes keeping track of the costs less than trivial, but we can at least get an idea.
Now I just have to wait for BPay "View" to be set up and we're all set. Also the electricity bill should be coming any day now.
Interesting to note: The amended bill is $31.37 - that made the geek in me chuckle inside.