You can update your scheduled payments in internet banking or the mobile app easily.
In internet banking go to Transfer/Pay > Schedule payments and click on the expand button (…) of the payment.
In the mobile app go to Pay >Scheduled, select the payment and slide from left to right to show the payment details.
A list of options will appear and you can make changes to the debit account, amount, date and frequency of the payment. Any changes you make will save over any existing scheduled payment.