MTN worst customer service ever

I have been struggling to get my MTN contract cancelled and switched to pay as you go. My contract has been paid in full in August 2023. I requested that it be switched over to prepaid when after a week or two my services has been suspended. I spoke to a lady named Lesego at customer service who informed me that there is an amount in arears since the contract has been changed to a month to month contract, without my concent, after i gave clear instructions 30 days before my contract ended to switch to prepaid. I was informed that if the arrears was paid it can be cancelled immediately, I paid the amount and called MTN again on 26/09/2023 asking that they cancell my contract and switch it to prepaid, I spoke to Nosanto, stating that it has been cancelled as requested. On 27/09/2023 I called MTN again and spoke to Noliso who confirmed that it has been cancelled. Today i get an sms stating that my account has been submitted to collections for no payment, I called MTN again, speaking to Yanda, where he stated that the cancellation was never submitted and if i pay the balance he can cancel it immediately. I feel that MTN is busy *****ing from me as the client and I am not getting any assistance from their side regarding the matter instead they treat me like a "cash ***" trying to get more money out of me.