Did you port your Optus Home phone number to the gaining provider, or were you setup with a brand-new number? If you have an established NBN service with one provider, you can ask the new provider to perform a "service transfer"
That'll result in the automatic cancellation of your old NBN broadband service. Depending on the technology type, like NBN FTTP - you can have up to 4 services from 4 different providers.
You'll definitely want to contact us to process the cancellation.
We might even be able to go in and backdate the cancellation to the date you were connected with the new provider.