What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
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.
I checked your two most recent submissions and it doesn't look like either one selected anything that would cause them to be charged.
You can set the payment field to be required:
This will force your users to choose one of the options. You can also individually require products in your product settings:
However, if nothing is required to be purchased, they will still be able to submit the form without payment.