In my 40 or so years with AGL, I have not received a bill perhaps 2 or 3 times.
Usually a reminder comes, and I have generally called them to advise the missing bill, they mark the account to waive the late payment fee, and reissue the bill.
This might have happened once with emailed bills I think.
Might be worth trying the chat service to do this, if the 'press x button' and waiting on the phone for a sometimes long period of time is something you'd like to avoid.