Contact Cancelation

Good Day i dont understand why the contract continues when its only a 24 month contact. i was not informed that it will go on via any form of communication. i called in once to have it cancelled and i was called back by a lady who said i could call back when i want it cancelled, and that i had already paid for the service. soon i got an sms stating that i owe. why does she say i have paid for it if im in arrears. then i would not have waited and cancelled immediately . i then tried on the date she infomed me and i still could not get through. when i finally got through. i came through to themba hamnca who told me he cant tell me his name until he carries out a security check. he blatently ignored my questions and notified me that if i do not do what he says he will hang up the phone. i requested to speak to his team leader Jameela. when i asked for him to notify me how long she will take as i would like to hold i was informed that she needs to call back 5 customers first before she can get back tom me.