Every so often a merchant will submit a transaction late, or a file will fail to get transmitted, resulting in such a delay. It does tend to bother some customers, particularly those that don't reconcile their accounts (they are the same ones who think if it hasn't shown up by day "X" they won't have to pay for it).
Unless your customer raises the issue of "unauthorized," the fact that the transaction is late is a non-issue. The customer should be grateful he had the use of the money for the extra time (90 days' interest at 0.5% on $100 is about 12ยข, after all
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