Capping data downloaded for day or week

Feel free to shift to appropriate forum area. Nothing looked suitable.

 

Other answers in your forum recommend going to advanced settings to set a cap for downloads, but this isn't an option with the Nighthawk M1 with its online settings as far as I can see. I've gone thru everything I could find.

Is there anything I can do to limit downloads?

I can't buy more than 90 GB with Telstra's diabolical plans and I was hit with $200 overspend on an $90 plan last month because my family aren't good at tracking their usage, and the SMS messaging on the device filled up and no more alerts were visible.

 

These device controls should help us protect ourselves, not enable ISPs to whack us with huge bills.