For 24/7 support message our team of experts via the My Optus app.
Hi
why am i being charged GST on top of my prepaid plans, nothing was stated in the sign up or conversation that i would be charged gst on top of my $80 and $40 plans!
There was a similar post to yours a few months back and I believe the issue was simply a billing error. Might pay to have a quick word with accounts to see if the same thing has happened to you. You can try accounts on the live chat link below if you wish.
http://www.optus.com.au/shop/notices/service-chat