Cell C is reaping me off.

Greetings. Today I got a call from Cell C from a lady called Diane, who was extremely rude and told me that I am owing R3500 with CellC which I don't understand because I last made payment in January and I tried to call Cell C for cancelation but the call got cut off and I tried a number of times to call them for cancelation but I didn't get any help and that's when she became so rude and told me my credit will look bad. And I asked how much do I need to pay for February and she rudely told me that she won't be able to tell me that as I must pay the whole arrears amount included and I must pay this R3500. But how can I pay this amount when I did make calls to terminate the contract but CellC was ducking and diving when they were supposed to cancel the contract. Mind you that data that they were providing me with I couldn't even used it the signal was very poor and it was not used since October 2022.