A customer is free to make a claim under Reg E for any electronic funds transfer which they did by providing an oral notice. In this instance, you investigation will be brief:
"The consumer admits to authorizing Western Union to charge their card $XXX.XX and the account was charged for the correct amount. This does not meet the definition of an electronic funds transfer error."
Since you already know the outcome of your investigation, there is no value in asking the customer to complete paperwork. Simply provide written notice to the customer that no error occurred as required by 1005.11(d) and move on.
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Sola Gratia, Sola Fides, Sola Scriptura, Solus Christus, Soli Deo Gloria!
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