Hello IJ. Are you referring to the breakdown in the My Optus App? If you take a look at the Data Breakdown page of the My Optus App, you’ll find a note that states '...Breakdown displays your total data usage, inclusive of any eligible data free services (e.g. included music and video streaming services) which you are not charged for. This page displays your total rather than billed usage. To see how much data you've used and how much you have left, please refer to the previous page. This page displays your usage and how much data you have left.