It's 100% intentional that mobile providers don't give you an easy way to see your overall data usage, right?
Like, Telstra gives you a bar chart of up to the last 3 months (not 90 days - if you were halfway through a month, you'd get 2.5 calendar months of data), but nothing more granular.
Woolies lets me view seven days of usage, or download a PDF of up to 90 days, all with mixed units and poor enough formatting I can't easily get it into a spreadsheet.
This is anticompetitive bullshit.