On my portal, it is under e.bill > Airtime detail. (inbound and outbound calls recorded)
Texts are under the e.care tab
On my Wife's prepaid it is under Account Activity > Transaction History (outbound calls only recorded)
Yours may be different, as Prepaid, Corporate and Personal accounts each have a different interface.
Your monthly bill, or the 'My Account' portal will allow you to see dates and times of voice calls. Your phone is the only location you can find a history of texts, as they are not reported in other formats.
EDIT: I see text history in my account profile as well, under e.care tab.