Refusing to close accounts - *****ing from clients

THIS IS THE WORST CUSTOMER SERVICE I HAVE EVER EXPERIENCED. I immigrated to study over 2 years ago, as one does I called to cancel my phone number/contract.(Also NO communication or attempt of payment occurred in these 2 years). Then my mother received news that I am about to be blacklisted for an outstanding bill for a number that hasn't been used in over 2 years and which I had cancelled. So 2 odd years later, this November 2023 I went into a vodacom store to ask what is going on. I called the help service while I was there on the 28th of November and cancelled the contract from December 2023 so I had 1 payment of an account which was suppose to be closed, but you know whatever as long as it actually gets closed. In December went into a vodacom store again to pay and confirm the account is closed. I paid and AGAIN IT IS NOT CLOSED????!!! So I called again on the 22nd of December 2023 and cancelled the number. LOL AND YOU WON'T BELIEVE THE NERVE!!! Now 9 January 2024 the first time since 2021 have I received communication from vodacom about an outstanding bill. Like at this point I have no idea what to do. I have the call reference numbers, at this point the ombudsman needs to get involved. The systems are not working and are malicious. What on earth is going on there, this is financial abuse and malpractice. The client's here are being taken advantage of. Why have I needed to pay for over 2 years for a number that is cancelled and still receiving bills? I just want this sorted. I will not keep paying for a service that I do not receive. I don't want the number as I have made exceptionally clear , I have no idea where the sim is even. I am a student and having to pay and fight with this unprofessional company is disgusting.