Fidelity ADT Small Balance Service Fee Credit Write-offs

Every ocassion where an overpayment on the monthly Service Fee exists, Fidelity ADT conveniently removes the amount using the Statement line item "Small Balance Write Off". Having queried this time and again there has been NO response, nor have the amounts be reversed. What Fidelity ADT is doing here is tantamount to *****, a befitting case should be opened with the SAPS. Perhaps bringing the matter to their attention via Hellopeter may invoke the corrective action needed.