Credit Card Processors/ISO's (independent sales organizations that resell processing) pretending to be a membership club with no markup. 

Most processors use the term "Enhanced Billing" when they charge a low “Discount Rate” then surcharge (over-inflate) the actual interchange rate. 

The processor made up a new fee called “Network Acquired Fee”. Since the processor places this in the Assessments section of their statement, it gives the illusion that the fee was from Visa or MasterCard.                                                                                                         

When merchants post refunds, the processing networks (Visa, MasterCard & Discover) return the Interchange to the processor.

When the processor removes the Processing Volume, the Interchange Fee can no longer be validated. 

The processor takes the 1000+ Interchange categories and divides them into three (3) Buckets:

1) Qualified

2) Mid-Qualified

3) Non-Qualified 

Zero Disclosure Billing is just that. The processor does not make up complicated billing techniques, such as Bucket, Bundled, Numeric, or Missing Category Billing, etc.