I am currently using a phone with an optus shared data plan with my parents, and it's under my Dad's name. I have recently - less than a week ago - bought a new phone - under my name - through the optus online store and requested to keep my old number.
It's been 3 days since it was delivered and the Sim card hasn't activated yet. It's a busy time of year so I get that there might be a queue, but when I tried to skip the line at www.optus.com.au/activate it told me "SIM number entered has been locked. A valid SIM is required to continue activation. Reference: PPACT-SIMVAL-0012".
I realised it might be because it's trying to take the number from an active Sim that's under someone elses account. Will my Dad have to deactivate my old/current Sim before my new one can actrivate?
The issue here is, you ordered a new service with number 123456 but wanted to transfer 386422 to you. This has made it exponentially harder. You should have done a "Change of Ownership" first, then upgraded second.
Step 1. Get the new number activated.
Step 2. Ask Optus kindly to transfer the number over from your dad's account to yours. It might be difficult as most carriers don't have a process for this.