Debited after cancellation

I cancelled my Life cover with Discovery, I received confirmation thereof on the 02/09/2025. Yet this month they deducted the installment again. I need a refund to be done, because this process is just frustrating, according to TCF you should not be making it difficult for the client yet here I am having to ask for this to corrected. how are recons done? This refund needs to be done speedily, I cannot and refuse to wait 10 days to a month for a refund.