When a payment is submitted from the Customer Portal, it is created as an Alternate EFT record with the SEC code "Web" selected.
Most commonly, this one-time payment will be processed in the next relevant EFT Generation processing event, where it will be included in the relevant payment file to be processed with the financial institution.
Sometimes, a Customer Portal user will cancel the payment in the portal before the related Alternate EFT record can be included in an EFT Generation processing event.
In both cases, the Payments value will be set to 0 and the Payments Processed value will be set to 1 on the relevant Alternate EFT record, so that payment will not be processed (or processed again, in the case payments included in an EFT Generation processing event).
Customer Portal - Customer Care - Customer Overview
You can verify that the customer cancelled the payment by logging in to the admin site for the Customer Portal, opening the menu and going to Customer Care - Customer Overview.
Search for the customer user by their name or email address, then click Payments. The customers payments will be listed in order from most recent to oldest. You can view useful information including the status of the payment, when the payment was created on the portal, and when it was updated.