Never take a telkom contact

I took a 24 months cellphone contract for R250 with telkom. I never missed a payment for the 24 months.my phone broke on the last month of the 24 months.i bought a prepaid phone and the telkom simcard did not have network/service in any other phone. They started deducting only R100 for their service which i thought ended with the phone contract. If not then when will it end?I contacted them to cancel the service but i was referred to WhatsApp everytime,the recorded message said i will receive a message that will enable me to talk to them on WhatsApp. Their simcard is not working in any phone i have access to so how can i see the message. I tried canceling on telkom.co.za but failed. In October 2020 i stopped the R100 debit hoping they will contact me but they never did and that will stop charging me. They only sent a text promising to contact me and a case number. In November 2020 they sent a message saying my account has been suspended due to collection. But they continued adding R100 per month even after the suspension. I received more than 3 calls from their sales consultants since October 2020 but they have no one to attend to their customers' problems. Now they are threatening me,i have to pay for services i was not using. My advise, NEVER TAKE A TELKOM CONTRACT