Unfair billing after 10 months of silence and refused cancellation

I app**** in November 2025, logged in once, and realised the course content was poor, so I stopped using it. The school completely vanished there was no emails sent to me, no invoices and no debits for nearly a year. Then, on 1 September 2026, they suddenly debited R720 from my account without warning. Now that I want to cancel, they are ignoring my calls, emails and WhatsApp messages, claiming that I completed 30% of the course just to trap me in a contract that they themselves breached when the failed to debit my account in 2025 and send relevant emails regarding the course I chose. This is terrible service and predatory billing. I want my contract cancelled immediately.