Please go to https://my.fantel.com.au
Enter your account number in the Username and then your password. Click Login button.
Then you need to know how much is owing by clicking on the My Account tab and then Invoices tab.
Once you have the amount, then proceed to the Pay My Bill tab.
Then enter the form shown in screenshot below. To save the Credit card on file make sure you change the Activate Auto Payments to YES. And then hit the Debit button.
Then you're done.