If you have paid by credit card and the debit does not work, it is possible that your credit card information is not up to date.
Please log in to your account and update your payment information. Instructions can be found here. You can update your paypal account there as well.
It is also possible that your credit card limit has been reached. Please contact our customer support so that we can reschedule your next charge date to a date when your credit card limit will be restored.