Unfair treatment over an account

I just had to give this company one star in order to be able to write a review. They don't deserve even a star. So I took a contract in August 2020 and after using the service for two weeks the WiFi stopped working. I called several times and kept being told it's a problem with the Telkom network. I called several times to know when the problem will be fixed and then I was told that someone will be sent to install an antenna to improve the connection. Nobody came. Come month end I was billed. I called them to ask why I was being billed for a service that they couldn't fix? Again promises were made and none delivered. I called in the next week's to cancel to no avail . I was told to hold and kept being transferred from one office to another until the last person I spoke to said he didn't work at Vox. Months end again I was billed. I now didn't know what to do . I was billed for the next five months until I contacted them via a comment on Facebook. Someone gave me a call. I was told that they would credit my account with the last two months of the bill. I asked why I was being made to pay for services that were never rendered to me and they said it was all they could do because the official email I sent to cancel was made towards end of November 2020. I said but that was so because from the time of calling them to tell them that I had connection issues, nobody attended to my problem and I kept being billed. There was nothing I could do then. This was in 2021 February. So I told them I couldn't pay the total of the then R800+ and asked to pay in installments. I indicated I couldn't pay in the next month. To my surprise end of march I started getting letters of demand and that my account had been taken to lawyers. I'm being threatened with letters now and now the account is almost 3000. So Vox couldn't wait for me to start making payment towards the balance that had been sent to me although unfairly so? How does this company operate really? How do you demand and threaten someone to pay for a service that they never got but had agreed to pay for just for peace sake? How come Vox is so quick to demand payment yet when I asked for service nobody attended to me?