Parasites

I registered for the free 1 month trial, however they are debiting my account non stop even way before the free trial started. I've cancelled the course with them as I am no longer interested. The agreement was R399 after the free trial of 1month. However, they have debited R499 before the free trial began. I am extremely furious with them. Can they just stop debiting my account for nothing and worst part is that I can't get my money back.