Frustrated for taking money that does not belong to them

I canceled my plan with then using their policies and procedures following their rules, waited 30 days notice and had an email confirmation to say my plan has been terminated effective 30 Sept 2025 but now they have taken off another debit order and refuse to refund me because of their negligence of not updating their system to my plan termination, I have been trying to contact their billing department but they only work via email and I have been waiting now over a week and no response on my refund. Legally they had no right to take that debit order as my plan has been terminated and I have the evidence to proof it, I had no hard feelings towards dischem health they were great but I needed full medical aid for my daughter the way they are treating my case is unacceptable. I would not recommend using them anymore.