Angry customer

I had a contract with them and was cancelled long time wth a consultant that wanted to upgrade my contract. Months later was called and told was in errors while i fully paid my cancelled contract. When i went to telkom store in west street a gentleman assisted me and my line was used by someone which i thought was long cancelled , he made me fill in a ***** complaint and was told they would investigate and line will be cancelled on to be called by 3 or 4 agents from debt in saying i need to pay 1000 now gone to 4000 because my line was cancelled with imediate effort like i dont get it how can i pay for something i cancelled long time and i was not informed and worse u explain from consultant to consultant the samething over im so ****ed abiut this it either they sort my account or this will be taken further.