CANCEL MY CONTRACT I OWE YOU NOTHING

I took up a phone/Playstation contract with Vodacom on the 27 Nov 2019 which ends 27 Nov 2021 and never missed a single payment. On the 14 October 2021 I sent them an email informing them of my contract coming to an end. I rep**** to the email of my monthly statements and received no response. December I sent another email after they deducted again. I went to a Vodacom branch to complain and was given a number to call but received no answer. They would not even allow me to use their phone but a gentleman gave me his phone to use as I don't have that SIM anymore. Customers in the queue told me it's very difficult to get through. I googled and emailed retention.cancellations but the address was not found and kept emailing the customer care requesting for someone to be in contact with me and to date no response. I reversed my money and now according to Vodacom I owe the R800. I was at their branch yesterday and the lady before me had the same problem. Why is it so difficult to end our contract one's we have reached 24 months next thing you will be blacklisting us. I have all emails as proof that have made attempt to end my contract 30 days prior.