The Optus staff that are active in the Yes Crowd do not have access to Customer Accounts.
With the current situation even if you messaged Optus via social media, I think this would be placed as a low priority.
The service you have selected is currently invalid
The few instances of that error that I have seen it required direct Optus contact to fix.
The only other thing I can suggest you try in the meantime is the billing section of the app.