Paypal form received without payment

Hello, 

I had a submission on my jot form but the payment didn't go through.  Is this something the user is able to bypass or was there an error with paypal?  Any help on this would be appreciated.  

The payment field is not currently required on your form. It means that the form user can bypass the products selection. In this case, the form will not redirect to PayPal since the Total is 0.

If your case is different, please let us know.