Refusing to cancel Netstar Go subscription

Last year I decided to try out their Altech Netstar Go programme. However after a few months, I realized I was paying for a service I was not using, so I decided to cancel it. Since October last year I have been trying to get them to cancel my subscription but apparently their processes and systems are too complex to cancel a simple subscription that 6 months later I'm still battling to get them to cancel it. Everytime I call they advise me that someone from their cancellations department will call me too confirm the cancellation, but I still have not been called. I even called them this morning but the agent I talked to could not help me either. If I don't get this one subscription cancelled by next week I will cancel my subscription with Altech as this is a total waste of my time and I'm running out of patience.