Audible.co.uk ******* !!!

I am extremely frustrated with this company. I tried their free trial subscription for a 3 days and decided to cancel because I was actually interested in audible books however it turned out to be not what I expected. After cancellation, today I wake up and they billed me R172.77 for no particular reason. It's so frustrating because I did not authorize them to do so, they are ******* !!!!! I tried deleting the credit card details on the website but it does not allow one to do so. This is frustrating and I am never ever doing this with people who are professional *******.