Block overuse of plan allowances

[Awkieschick]

I would like to know if there is anyway in stopping the use of my plan once I have used up all of the allowance? I am sick of the expensive bills and would be really handy to stop it.
Thanks

[Caaf]

Hey there,

I assume you mean mobile? So I take it you've not changed over to the auto top up?
https://www.telstra.com.au/latest-offers/extra-data

Failing that, convert to prepaid as you can only go as far as your money allows.