Unable to cancel policy

I have been trying to cancel my car insurance this whole month and every time they hear that I want to cancel I am told that I went through to the wrong department and I should hold for the cancellation department. After a few minutes of holding the call just gets hung up. I am frustrated, my premium increased from R1200 to R1600, I will not be able to afford this so I got a cheaper premium somewhere else. I have made the decision to block the debit order until they call me because I don't know what else to do.