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 have checked your form submissions and I can see there are not duplicated forms, upon checking your form I can see there are two email notifications that are being sent to the same email address:
You can also set unique submissions on your form, here's a guide with more information about it: How-to-Set-Unique-Submissions-on-a-Form
Besides that, you can also set unique questions, this way you avoid to get submissions with the same info, here's also a guide about this: How-to-set-Form-Limits-Based-on-a-Unique-Question
Hope this helps.