Last week I changed my BYO sim to another provider, and was logged out of my Optus app automatically.
I’m trying to find the September bill for payment, OR does cancel anytime literally mean you can cancel at the end of the month and you won’t be charged for it?
I also still have a fetch box I pay for so my service being completely dropped completely is incorrect isn’t it? How do I pay for fetch and main ring my fetch subscription?
You need to have an elligible Optus Mobile or Optus Home Broadband plan to use the Fetch Box. If you don't have one then you'll need to return your box to Optus or they'll charge you a $250 non-return fee) Contact LiveChat and they'll send out a prepaid courier bag for you to do this. If your old SIM is defunct then you'll get your last bill shortly via the usual methods (emailed to you?)
You should be able to still log into MYACCOUNT here online (or contact LiveChat) to get your remaining bill.