Optus will always send out a monthly bill (its a legal document). You have set it it via email?
If the account is in credit then I'm not sure how Optus approach it. The general rule is that Optus will draw down on the credit amount before needing to get any left over. However I'm not sure if you need a direct debit in place for this to happen automatically. (Note without a DD you will definitely be charged the $2.50 fee regardless of your credit status).
Thanks Peter. I had direct debit in place which is how they took out the cancellation fee for a service I never received. That have confirmed that but can not direct credit me back. They only can syphon and not return. Optus stopped my direct debit. They also advised me I will have to resupply all the details and restart it manually when i owe them money for services in 10 months time.
Now they send me reminders for the monthly service if $60 when I am owed nearly $600 from them. This relates back to incident from October 2018. I have spent over 100 hours on hold and talking to numerous people. They tell me its all sorted, confirm its correct then end of the month....BAM its back to jumbled.
It is astonishing that something so rudimentary to running a business can't seem to be properly actioned..
However Optus can't keep money that is not theirs and its a general request for the amount.
I'd suggest to save time on the phone (although a bit late for that) you should write a formal request / complaint. These are treated more seriously than other modes and you get a complaint number and hopefully a solid resolution. If not then you can send the letter to the TIO.
Customer Relations Group
PO Box 306