It happened to me too. I have just received the bill and I got shocked when I saw 5 transactions of MIA Sphere Live for Top 10 Service which i didn't sign up for and i have no idea what it is for.
I have been with Optus for more than 5 years, this is the first time it happened to me. I have tried to call Optus since this morning with no luck and also tried to contact using the web chat and also no luck.
Hope Optus can fix it and refund these unauthorised charges to my account.
Not a happy customer!
Feel free to send me a private message if you still need a hand. My inbox is a little flooded at the moment but if you include your account number, full name and DOB, you can leave it with me and I'll get back to you asap.