********** Debit Order

For the past 7 months Mercantile Bank have been **********ly debiting my Standard Bank account with varying amounts from R50 to R2 060 with the reference MLBCCD*** on the 26 of every month. My debits only start running from the 27 of every month. When I call standard bank to reverse the transaction I am charged a bank fee of R200. I called Mercantile Bank several times but they were unable to help me. Both banks seem unable to assist me in resolving this issue.