For 24/7 support message our team of experts via the My Optus app.
I just received an invoice that I didn't expect. I cancelled my service two weeks ago and I just received an invoice for another full month.
The Optus staff that are active in the Yes Crowd do not have access to Customer Accounts.I suggest you have a look at this link https://www.optus.com.au/for-you/support/feedback-and-complaints
At the bottom of the page is a mail address, write a letter and attach any supporting documentation of the cancellation.