Cancellation of ShowMax

Good Day,

I have a problem with Showmax, i want to cancel it but i cannot login. I find it very ironically because when you want to signup, it allows you to do so, but when you want to cancel it, you cant. I tried using my phone and pc to login but i have failed, they links on the page are not working. I have been charged for the service that I do not need. I signup for the trial when i want to cancel it doesn't allow me. Please help