Unauthorized Debit order

This Morning when I woke up I received a notification from my bank with a reference number GR LIFE/GR LIFES62387 that was trying to debit R99.99 from my cheque account. In the past R97 was deducted from my account and I had to go and stand on a que at the bank for a debit order reversal, This company must never again debit my account, I don't know them, they don't know me. Let this be the last time....