RAIN

Had the worst service with rain!! I called in to ask them to cancel my subscription as I no longer need their services anymore I'm always struggling with network coverage hence the cancelation, however I was told I have an outstanding amount of R499 and I never used their service December and January, what I would like to understand is that is rain a contract?? What agreement did we have?? Because I feel that if I don't pay the monthly subscription then I won't get internet services right?? I honestly would not advise anyone to go for rain it's the worst!!!