Being Charged for a cancelled policy

I have sent about 10 emails now regarding this policy. It was cancelled in April 2017. Yet they still charge me every month R236.00 per month they had sent me a confirmation that the policy has been cancelled but I cannot get anyone to assist me in stopping the debit order. I also need a refund for all the payments made since April 2017. I only had one reply and that reply said the policy was cancelled further to that all my emails has been ignored.