MiWay representing a Stopped Debit Order by increasing the amount slightly.

A vehicle was purchase and Insured through MiWay. Since the vehicle was Insured for Business purposes use we obtained more quotes and was offered better benefits at a lower rate than the MiWay tariff. They were notified and their Debit Order forthwith returned and a Stop Payment put on it via our Bankers. The following month MiWay represented their Debit Order by increasing the amount with R2.00 and some odd cents and it was deducted from our Bank Account without the option to return it again. What do we do about this lost premium?