I'm sorry to hear that you're considering discontinuing your service with TPG. We can organize a call from our Escalations Team about your request. Please PM us the following details so we can arrange a call back:
However, since your goal is to switch to NBN, we can actually have our Change of Plan Team assist you instead.
Let me know how you'd like to proceed.
For your reference: How do I private message (PM) in the community