Cancelling of my contract

What a disgrace of a company. They are the worse of the worse and they prove themselves each and every time. My contract expired on the 16th July and I paid them the R300 on the 27th July, when I email them the cancellation they said that I need to phone their call center. That is just a cheap way of them to worm them out of any paper trail I assume. Anyway I did phone the call center and the agent offered me a prepaid deal of R100 every month of which I declined off course as I could get a cheaper deal at Telkom and I told him I am not interested and he should cancel my contract please. I assume that the contract has been cancelled but to my dismay when I went on my credit score I saw that I am in arrears with my vodacom account, but how can this be because I cancelled my contract and I am not even using that cellphone number. So I immediately send Experian a dispute and a copy of the payment that I made on the 27th July, and I send another email to them with the POP, but as usual they are not responding when they here about cancellation. This morning 28.10.2022 I tried again to phone their call center and all of a sudden the call center said that the reception is bad they will phone back, but when they persue you with a new contract there is never a problem with reception. You can take me to court but I am not paying you a dime of my hard earn money for a service that I am not using. I am waiting for you we will see each other in court.