Ellen, a couple of things to check.
There could be estimates being made, and usually they are a lot higher than normal use for some reason.
This applies if you have an old analogue meter(s), and there's usually a reason (dog, locked gate, etc) . . . usually digital meters are automatic and reliably send your data to the supplier and then the retailer uses that for your bills.
On your bill, it will tell you if the past 2 months have been actual or estimated reads.
Usually on page 2 just under the date range for the bill, if will say "Electricity charges are based on an actual read." (or based on an estimated read).
If analogue meter(s) and an estimated read, you can upload a read of your meters yourself, and get this corrected.
https://www.agl.com.au/help-support/energy/meters-and-reads/reads/submit-a-meter-read
Another thing is are you on the same plan, fixed tariff or TOU tariff . . . as well as still on same meter(s) as before ?
Rates are very different for fixed with peak and off peak rates, compared to TOU (time of use) rates, and possibly benefit you more / less.
Power bills are increasing far above CPI, but if only the past 2 months bills are much higher you should be past the big rises that happened prior to that, when increases of 25% were common.
Good luck finding the cause and hopefully sorting it out for the next bill.
