Unprofessional ,rude and harassing

I am writing to complain about your harassing phone calls and poor service. I received a call in November saying I owed a month on my DSTV -which I disconnected in 2017. My DSTV was on a debit order for YEARS , and I called to cancel my DSTV through their call centre . Please note my DSTV was on a debit order.!!

How do I owe a month, and if I do , where is the supporting documentation /e mail / proof etc ?? I have never received any notification from yourselves in writing - after my requesting this twice ! Which month do I owe for, why wasn't it taken off my debit order, why was my last month not debited by Multichoice - the questions are endless.! Can you please be a bit more professional apart from your endless phone calls ! I live Overseas - so my South African cell phone number does not work any longer - someone has the number. Can you send me some sort of statement and paperwork on what is outstanding and I will pay the bill should it be outstanding? Ps; your callers from your company are also rude an unprofessional.