Optus migrated my service from a working ADSL to NBN at 10:00 on 28th Dec, 2018. Absolutly no NBN or Land Line since that time. Now 15:00 on 25 Jan, 2019. I have given up contacting 133937. They appear to exist to simply send customers around the world with no outcome. In 7 hours of contact over 2 days I was asked to give my identy 8 times and passed on to someone else. I have 3 other phone numbers who seem to offer the same non service as 133937. Contact was made with a Customer Service person in Adelaide and though they promised a lot, I am still without NBN and Land Line and possibly no connection in the forseeable future (Optus offer no evidence to dispute this claim). Seems Optus (NBN Component) are a company who regard their customers as an inconvenience. Mobile phone service is totally different and could recommend them.
Optus Case #20373218. TIO Case #7482119
That sounds like a nightmare case.
I would formally request the contract be terminated. Find another RSP that can
a) work with the NBNCo and more importantly
b) take ownership and provide specific feedback on exactly what is going on.
PS Agree the Optus Mobile Network is technically a much better run system. If they find a way to eliminate uncontrollable excess usage charges it would get an A.