Vodacom is finessing my fibre contract cancellation.

I had a fibre contract with Vodacom, they then disconnected my line and still charged me an extra fee for the next 4 months. I submitted a request for cancellation in December and they stated they did not receive it. I then tried calling but no answer and finally submitted another cancellation request. They emailed me asking for details and I rep**** on the day with those exact details and today they email me stating that I did not reply and the request for cancellation can not be complete. What nonsense is that, I even have screenshot evidence of me replying to that email with the exact details they needed. Now I must await another month and get charged for another months fee, keep in mind I am a 19 year old student earning less than 10k a month. Could Vodacom be so ridiculous by trying to drag me along as a customer for a service I can’t even use. The employees at this establishment are as useless as the company itself. Fix this problem before I get higher power involved