Contract cancellation and credit bureau delisting

I took a explora decoder last year 2019 between Aug-Dep with ON Air however the agent tried to outsmart me saying I will record without any monthly fee as I'm already paying for it. within a month I called them to pick it up as it was not as promised it took over 3months for the pick up, once that was done I asked them not to debit my account as decoder was collected and they can close the account. Recently I tried applying for a cell phone contract and was told I'm owing on air worst of all they blacklisted me. How was I blacklisted when no payment communication was made by them nor letters from their lawyers/collectors were sent? I have been calling none stop with Angashley and Vinashi who is the team leader assisting both of them have been useless and lying to me daily as I'm still waiting for apology and settlement letter from their management. Due to their negligence I find myself listed with a debt or contract which was cancelled before been used. I demand all the relevant parties to be punished for failing to conduct their job properly. I will not leave this hanging till that happens, I will do whatever it takes to ensure my name is cleared even holding people hostage cause people work better understand threat and dangerous situations. I'm only giving ON AIR 7days to remove my name from credit bureau, send me those letters and furnishing me with information of what will happy to the people who were negligent with the situation.