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.
Please do check this guide regarding incomplete payments:
Please do take note that clicking "Complete Submission" will not process any payments, this will just add the submission in your completed list. The reason why you are having incomplete submission is that users might have accidentally closed the browser when they are in the payment gateway or they changed their mind and did not proceed on the payment, this means that a transaction never existed.
To check if the submission has a payment, I believe you will need to manually check your submission list and cross match it with your transaction history in your payment processor (I'm guessing you have integrated Paypal).
Do let us know if you need more information on this.