This is a public forum, not a service centre. As it sounds your request is legal in nature, possibly best to forward this request to Optus via their written customer service contact point.
Customer Relations Group, PO Box 306 Salisbury South 5106.
You mentioned this request has already been done for your wife's number so it should be a simple matter of contacting Optus again and requesting it for yourself.
Have you tried to login to My Account to view the bill for the desired period? If it is an itemised bill you should be able to do this via self serve.