CV Wizard Overcharged Me After Cancellation and Offers No Customer Support

I had a monthly premium subscription with CV Wizard, which I cancelled on 19 January. Despite cancelling on that date, I was charged again today in the amount of R299.99 on my bank card in South Africa. This payment was taken from the account linked to the email address tekanereale****@gmail.com. I have not been able to contact customer service because I could not find a contact number. I request a full refund of the R299.99 that was charged after my cancellation and a clear written confirmation that my subscription has been fully cancelled and that no further charges will be made to my bank card.