Cellphone Billing

I have a Cell C Cellphone contract *** My Contract of 24 month ended on August/September so I have an Outstanding balance of R754 something which I'm gonna settle on the 6 Dcember when I called their consultants to make an arrangement they further billed me another subscription fee R 1000 for the month of October which they tell me that I the subsription is recurring monthly and I cant cancel since my Account is in arrears but I dont sunderstand why should I be paying a recurring subscription fee whereas my line has been cut off and my contract relationship ended on August/September why should I pay for something I didnt use I find that to be very absurd and no Customer Loyalty and breach of contract.