Thanks for contacting Facebook.
Unfortunately, we were unable to process your last payment. You can re-attempt the charge by clicking the ‘Pay Now’ button in your Billing Summary:
https://www.facebook.com/ads/manage/billing.php?ref=cr
If the charge continues to fail, please add a secondary payment method and retry the ‘Pay Now’ button. If all attempts fail, please contact your bank. Often times, the bank may decline the charge, but they don’t give us much information about why the payment failed.
Please let me know if you have any other questions.