Unable to cancel policy / debited after cancellation

In October 2020 we were going to switch from Outsurance to Discovery Insure. However, we decided it against it and cancelled with the Discovery Broker. Yet, they still debited my account on 15 October and 15 November. I had to go to the bank to reverse the debit order. Today I went through my ban statements and saw that they DOUBLE DEBITED me on 15 December!! They also debited me again on 15 January and 15 February. This is after we were told in November that the policy has been cancelled. Who is running that clown show? Also, will I be able to reverse debit orders dated that far back?? We have all the proof and documents that we cancelled the policy.