Joomla Component not saving entries in admin section

Our payment form is here: [login to view URL] When we try to add a new payment from the admin section: Components > Payment Form > Payments > New It will not save the custom field values. Any standard fields (first name, last name, email, address, etc.) are all saved correctly, but any custom fields are left blank (see attached screen shot). We need to be able to add new payments from the admin section because sometimes people pay with cash and we have to manually add them. This project is to fix this so that all fields will save correctly when adding them from the admin section.