Welcome to the Community!
We were able to locate your account using your community details and reviewed the plan change request.
It shows that the maximum speed that you are able to receive using the current infrastructure (FTTN) is around 24 Mbps Downstream only.
This explains why the NBN50 plan was not activated for you.
We understand that you've upgraded to the NBN25 plan instead and it will be applied once the NBN50 upgrade request is successfully removed.
Let us know if you need further assistance.