Rain - Month to month contract is useless

I was contacted by 2 consultant, Dorothy and Malibongwe from rain demanding money from me for service that i did not use. Again it does not matter whether services were used or not, as it was meant to suspended a long time ago. I would not advise anyone to use Rains services, especially when you want a month to month service. My rain services has been on not sure whether it is 2 or 3 months straight with no payment made, I have been sent payment reminders thinking why are these people not cutting the service as it was said in the terms and conditions. Now I am being called for a whole R1800 that I need to pay because the services wasn’t cut and I haven’t paid. When I took the rain I knew I am not obligated because services gets cut when I don’t pay then I won’t be in debt.

Why was the account not suspended/ or cancelled or disconnected upon not receiving payment from the month as clearly stipulates in the T&Cs? Kindly assist in providing a way forward regarding this, as I would prefer this matter be resolved timeously