absa vehicle finance

I own a vehicle financed through absa finance. My normal debit order premium is approx. R3700 a month and has been debited as such for the past two years. My last debit order deduction has now increased to R4700. I spoke to a collections agent today with whom I asked what the extra R1000 was for. The agent proceeded to inform me that it was insurance. I said to the agent that I had existing insurance and who authorised absa to initiate this deduction. The agent proceeded to inform me that a message was sent out informing me that they would be adding this insurance to my premium. He proceeded to tell me that it was added because I did not reply to the message declining the insurance..what a **** absa. I want answers...who authorised this transaction as this is *****. This has also cost me R120 in a debit order return. I will be contacting 702 to debate this issue and to warn other absa customers of this ****....very dissapointed!!