Just bounght a new SIM expiry date 7 Dec 2020. Try to enter the number in the Activate screen but get told "The SIM serial or service number entered is invalid or is already active. "
Tried calling for Activation assistance but the options are more useless than a choclate teapot and I can't speak to a human.
What next?
Try calling TELSTRA. They helped me last time I was porting a number to my new Boost SIM.