You can change your payment method in a payment modal window on Transactions that you see when you click on a “Buy Credits” button.
- You will see your current payment method on the top and a link to "Change payment method" on the right of that box.
- In the next screen click "Add Payment Method".
- Enter your payment details and save with "Add new payment method".
- Close the "Buy Credits" window clicking on "Cancel" if you don't wish to purchase credits.