Sorry to hear about your experience. Have you tried calling your original provider incase they are not letting the number go, or it could be your porting details are not matching from your original provider. Can I ask what provider you moved from ?
We did have a porting outages impacting "same Carrier" port ins.
They're numbers coming from carriers that use the Optus Network to supply service.
We've since been advised that the issue has been resolved. The suggestion you've been offered doesn't sound right.
I'll send you a private message.