If you are experiencing financial hardship and late for paying your bill, then with out any notice Optus restrict all incoming calls and all outgoing calls, how do I call Optus to rectify?
Probably best pointing you to the hardship policy: https://www.optus.com.au/about/legal/financial-hardship?sid=short:financialhardship:fy2018
Pretty sure you can still call Optus even if all other calls are barred.
It sounds like the OP didn't claim Financial Hardship prior to being barred.
Good suggestion to use the app in future to try and prevent this.
The bill usually states if there is an outstanding overdue amount service restrictions can apply.
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