How can I see payments associated with a form?

You need to go to the submissions page for your form, this guide will help with that: How-to-View-Form-Submissions

Once you're in the submissions page you need to search the payment field, there you will find the product/s purchased, the paid amount as well as the payment info, here's a screenshot about how it looks: 

I have checked your forms and noticed the payment fields are not required so may be that some of your submissions do not have this payment info and it means that there was not payment sent. 

Please if you have any question, let us know.