Poor service and incorrect billing and premature escalation

I contacted the call centre to request a cancellation of my contract which was ending on 31 Jan 2023. The consultant advised that I should call back on 02 Jan 2023 or I would pay a penalty fee. 02 Jan 2023: I contacted the call centre to request a cancellation of my contract which was ending on 31 Jan 2023 and was informed that because I didn't call earlier I would need to pay at the end of Feb 2023 as well. Needless to say, I was not happy about this, but I agreed. 31 Jan 2023: My bank account was debited by Vodacom for the instalment amount of R837.02 11 Feb 2023: I received my Vodacom statement showing the payment on 31 Jan 2023 for R834.02. The statement displays an amount of R258.01 as the total due to be paid via debit order on 28 Feb 2023. 28 Feb 2023: My bank account was debited by Vodacom for the amount of R258.01 10 Mar 2023: I received my Vodacom statement showing the payment on 28 Feb 2023 for R258.01. The statement displays an amount of -R0.10 as the total due. 24 Nov 2023: I received an SMS saying that my Vodacom account was in arrears with an amount of R359 (and some cents) which I ignored thinking it was a **** because I paid up my Vodacom account and cancelled my contract earlier in the year. The SMS bothered me so I contacted Vodacom customer care. I was informed on this phone call that my account does show R0.00 due but the account is with legal and the consultant will call me back with a final answer on Tuesday, 28 Nov 2023. An agent from MBD called me and I tried to explain the situation to him, but he was rude and insistent that I make an arrangement to pay. Another agent from MBD contacted me and again explained that I escalated the matter to Vodacom because my account should not be in arrears and she insisted on a callback. I dropped the call on both MBD agents because they were rude and would not take the reason into consideration. 26 Nov 2023: I received an SMS saying that my query is in progress. 27 Nov 2023: I received an SMS saying that my ticket (***) has been closed. I attempted to open the link in the SMS, but the link did not work. 28 Nov 2023: I contacted Vodacom customer care to find out the resolution of my ticket and I was informed by the first agent that the account is with legal and she cannot help me and she cannot see my statement, but she could tell me that I called recently (within the last seven days). She advised me that she could only transfer my call to the collections department. She transferred me and I spoke to another lady who said she couldn't I needed to contact MBD and ask them for a paid-up letter. She also stated that she could not see my statement because my account had been handed over I must contact MBD. I asked her, how the account be handed over if I paid up the account and the contract was closed and she responded that the system decided to hand the account over. I then requested to speak to her manager and she informed me that her manager was not in, then I asked to speak to another manager and she responded that I could not, but she would ask the manager to contact me. I insisted on speaking to the manager and she said that's not how they do it there. I gave up at this point and agreed that her manager should call me and for her to transfer me to MBD, the line cut and I have not been contacted since. I received another SMS this morning from MBD stating that my account is in arrears, this is borderline harassment for a system error on Vodacom's side. I have a cancellation quote and a zero balance. In actual fact I am owed a 10c. On top of that the call centre agents are clueless and not knowledgeable and extremely rude both from Vodacom and MBD. No time to hear my concern and unwilling to assist. I am at my wits end as they keep calling for money I don't owe and its borderline harassment. Why am I also getting called 6 months later???????? I have the necessary statements and quotes.