Hi @adamssanity,
Thanks for raising this to us. You can do it online, we did an article that you may find helpful. Please see the link below.
Changing NBN Plans through My Account
Let me know how it will go and should you require further assistance.
Cheers!
I'm looking at downgrading my internet speed from NBN100 to NBN50 and I was just wondering if since I have paid for the 100 already if I drop to the 50 will I have to pay another $69.99 or will the $89.99 I paid for this month cover it and just pay $69.99 on my next billing date?
