I requested Vodacom to change my business contract to a prepaid contract on 27th February

I requested Vodacom to change my business contract to a prepaid contract on 27th February. I received that the prepaid contract would take effect on 31 March, Bad service from Vodacom. I requested Vodacom to change my business contract to a prepaid contract on 27th February. On 2nd April I noted that Vodacom debited my account in an amount of R1053.50. I disputed this and Vodacom rep**** they only received the request after the 15th. I once again disputed this and added correspondence of my cancellation and Vodacom's reply, to no avail. Surely it is not my fault if Vodacom gave notice after the 15th March. I feel I am entitled to repayment of my money as I was in line with rules and regulations regarding changes and cancellations of my contract. I cannot be held responsible for a mistake made by Vodacom. Advocate L J L Visser