I don't believe Reg E or VISA gives protects the bank based on the level of intoxication of the customer. Since VISA requires you give provisional credit in 5 business days, which is more restictive, I believe you must credit the customer after the five days. If the merchant refutes your chargeback with a signed receipt bearing your customer's signature, then revoke the provisional credit. If this creates an overdraft and you can't collect, turn your customer over to Chexsystems.
Unfortunately, this is the risk of offering this product.
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