Superprof: Difficulty in canelling subscription

Used this site to find tutors for my son. Paid a monthly fee of R99. After we found satisfactory tutors, I wrote an email to cancel my subscription. On 27/3/25 I received a mail from Superprof stating that my account has been closed. The installment goes of my credit card and each month it’s still going off!!! I did send more mails, but with no satisfaction! I find this really hard to understand and completely unacceptable, and my only option is to stop my credit card and pay even more unnecessary costs!