Hey @Benputy,thanks for reaching out! For prepaid services, we don't keep record of your last three months worth of outgoing calls. If you've registered the service for Optus.com.au/my Account, you'll find a detailed view of all calls and messages to local, mobile, national, international, 13/1300 and premium numbers. You'll also see the time, date and recipient's number. Access is limited to 60 records for prepaid services.
There’s more info available here → http://www.optus.com.au/shop/support/answer/how-to-view-or-request-itemised-usage?requestType=Normal.... Shout out if you have any other questions.