Failure to reach Telkom for Cancellation of Contra

I have a telephone account with Telkom ***) which was transferred from my previous residence to the new one. Upon realising that I can no longer afford due to unforseen financial circumstances I have tried to contact them for cancellation for the past 3 months I'm not getting a response from the 10210 number as they informed that i can only cancel on the last day, now the bill is increasing drastically, according to my contract with them I have been paying about R198 everymonth on top up, but surprisingly over 3 months and according to the smses that I'm receiving I now owe Telkom about R1000, I have never received statements that explains how it got to that amount. I cannot afford R198, how will I afford R1000. How does one reach Telkom cancellations and disconnections to answer the phone to cancel this service before accummulating more debt and how do you bill someone without informing them of it.