I am not an employee of AGL (this site is basically a blog, where registered users and anyone in the world can read) and suggest that you look at your previous bill and see if your last bills are Actual or Estimated.
If this bill is Actual and the rest are estimated then you are playing catchup.
I suggest you read your meter and write it down, then compare the meter read you have just done with the the reading on the bill.
Unfortunately, gas meters do not read your actual consumption, but is calculated using the reading of the meter and a few other things to calculate the Mega Joules you actually used, which is what you get charged for.
I believe that you have recently undergone a price change and if you did not complain about the pricing structure then you would be on the highest rate.
Be prepared, as you will have to phone or chat which AGL to get this resolved, the longer you leave this the more you may be charged on the next bill.
Sorry I can not be of much more help, just trying to give you a hand in resolving this billing issue.
Hi @Mumofboys75. Thanks for reaching out. Sorry to hear your bill was higher than expected. There can be a number of reasons for a higher-than-expected bill, and we cover a few things you could check on our Unexpected high bill help page.
For help with reading your meter, check out our Help page about How to Read Your Own Meter.
If you wish to submit your own meter reads, you can learn how to do that here:
Submit a Meter Read
If you have any more questions, I’d be happy to help.