Company gives a bad service. My credit score is affected

This company misleads people. An agent phoned me on the 20th of November 2024 selling me a decoder I told her my tv is a smart tv. She said I’ll only pay R100 to watch all channels for free which was a lie. When the delivery came as I installed the decoder it turns out I need to pay for all channels, after I had told the sales lady that I already have a smart tv.. I then laid a complain, they took their decoder back wanting charge me for that, I told them it isn’t my fault they sold false information. The great thing is all calls are recorded so they couldn’t defend themselves… Now my issue is this company is ruining my credit score report it says I am owing over R2000 for it. I need it cleared out immediately as I’m also trying to build my credit score. I am not happy with their service they hang up when I call the customer care they don’t respond on WhatsApp. I don’t know what more I should do, please kindly assist me with this matter