Cancelled line _ not really cancelled because Telkom!

I honestly don't understand how this place can still be operating. Not only do they have the worse service their customer service is pathetic, I am just disgusted. I cancelled my line last year and now 4 months later I get a message about lawyers and ****, I then contacted them to find out what was going on and they said the line is still active. I then explained to this retarded agent that I had cancelled the line last year already how is it possible that I have an outstanding amount and why did it take them this long to contact me. Anyway I then told them to cancel the line and send me the final statement and a cancellation document. Now I am requesting proof of my cancelled line and they say they can not provide it. WFT... what if they do this again to me and I do not have proof ..? Because they did not give me proof. Now I am in a constant battle everyday asking for cancellation document because I need proof of my line being cancelled. There is no words to describe my true hatred for this company they are the worst of the worst.