If you would like to update your billing information, you may do so under Account Info in the Settings tab in your admin portal. Then, scroll down to "Billing Details" and click on the "Edit" button.
Then, edit the relevant details and ensure that you have inputted all the required information.
Remember to click "Save" once you are done!
If you would like to update/ change your payment account OR update your personal details, do submit a ticket to us on Zendesk as these changes cannot be made in the admin portal.