If you have a monthly payment plan, you can update your payment method by logging into your account here. Note that if you have not activated your account the system will not recognize your email. Follow the create account flow if you need to create an account. After logging in you will select manage plan, and look for the option to update your payment method. Follow the prompts to update your card information. You can also contact customer service to receive an email with a link to update your payment method.