Read this now, page-100

"For any third party charges you need to contact the actual third party that has billed you. These are not charges from Telstra. The charges on your bill will tell you the name of the third party and their contact number. As Telstra have not charged you you need to request a credit from the company that did, whether unintentionally or not at some time a third part has been enabled to bill you through your mobile service. Things like wallpapers, apps, ringtones, games etc are all third party services and can bill you through your mobile phone bill"

Tommy
Moderator
24x7 Digital Customer Care https://crowdsupport.telstra.com.au/t5/Android/MIA-Pty-Ltd-fraudulent-charges/td-p/299561