How To Cancel My Account

Hi, I tried using using Shaw Academy after the Vodacom shake thing recommended them and thought that it would be a legit Academy after I Joined the free trial, I started the course and then got this heavy aggresive marketing mails from them. I then what I should've done before joining, started to look for reviews on this Academy and it is horrible absolute chaos in their reviews, why this company is still allowed to carry on taking peoples money is amazing. But my main ISSUE is i can't seem to cancel. I must call a number with a reference that is pathetic they can quickly take your money but when it comes to canceling they make it soo hard.. Can anyone assist me on cancelling before they start deducting..