Multiple debit order deductions

I have agreed on a new policy with Platinum life on the premise that the first premium will only be deducted once I receive the official documentation and have gone through this. However, I never received any documents and on 1 May 25, Platinum started running a debit order. I am not using the bank account anymore and they have since then continuously run debit orders (up to 4 times per day) - so far I have accumulated R2800 in penalties from the bank. I have not given them any permission to do these deductions and need this to be rectified asap.