We appreciate yu raising this concern to us. We'd like to know what happened in this instance and assist in the best way we can.
If you are trying to change your plan, you may do so by logging in to your TPG My Account. Here's an article we created: How to Change NBN Plan Online via TPG My Account
Otherwise, let us have your Customer ID or username via private message in order for us to assist you accordingly.
We apologise for the inconvenience caused.