JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
You may follow this guide and update your payment method, it should allow you to update your Credit Card information: http://www.jotform.com/help/330-How-to-update-my-subscription-s-payment-method.
Do let us know if you are still having issues.