Visa's zero liability policy applies to debit card purchase transactions that are processed on the Visa network. Because that policy is more protective of your customer than Regulation E is, the Visa provision controls. Regulation E sets out the minimum protection you must provide your customer. It does not prevent you from adhering to Visa's more protective contract.
There's no conflict between the regulation and the Visa rule on this issue. You can comply with both by adhering to the Visa rule.
John S. Burnett
Fighting for Compliance since 1976
Bankers' Threads User #8