Optus do not give the option of turning off the auto data top ups.
Click on this link to see previous discussion on the topic:
Apologies for the delay in response, @Lou71. Optus automatically adds extra data tiers when you exceed your data allowance to avoid excess data charges and bill shock. In saying that, you can definitely check / control the way you use data by using the My Optus app on the device itself. Also look out for usage alert emails when you hit 50%, 85% and 100% of your data allowance.
I want to disable the $10 1gb auto top up data. Is there really no way to disable this. I think we are being scammed here! The notifications come to late ( in delay) and the top up has happened before I even get the notification that I'm am over data limit. This is not ethical. And is a massive scam. You hide behind the fact that you don't have the technology to make it real time but are happy to charge.
My issue is this, when I am at home I use my WiFi and it’s crap. Constantly drops out or very slow so even when I am using WiFi, when WiFi drops out and it’s switched to 4g. The bad part is, if it happens when you are watching YouTube or downloading a large file then your mobile data runs out. This month I have been charged 90 dollars and I am angry. If Optus is meant be providing better customer service they could easily suggest that I am better off getting one of their prepaid data only plan for 60 dollars which gives 30Gb and last for 90 days and unused data get rolled over. This data top up a well calculated scam to ripoff customers. I have spoken to Optus customer service and their explanation is that it is build into the system and they can’t do anything about it and she wants me to download data management app from the App Store to monitor my data and when mention I already got the myoptus app which is useless because it does not update accurately, she insisted I should download the app. I ask for reference no for the conversation to be text so I can have a chat to the communication ombudsman, she was very happy and I did not receive any text with the reference no. When it come to customer care, if you happen to talk to some foreign customer care person, they are very defensive and not very helpful, but if it’s a locally based customer service you get better service. Optus customers service Sucks.