6. Correction of an error. If the financial institution determines an error occurred, within either the 10-day or 45-day period, it must correct the error (subject to the liability provisions of §§205.6 (a) and (b)) including, where applicable, the crediting of interest and the refunding of any fees imposed by the institution.
If the original ACH debit was unauthorized, you must refund the fee regardless of whether you previously returned the item.
The opinions expressed here should not be construed to be those of my employer: PPDocs.com