Contract Cancellation

My contract ends on 7 May 2026, I called at thr end of March to give notice and was told I need to call back on the 7th April 2026, as it too early to cancel and to make it 30 days, as contractually stated. I called on the 7th April 2026 and canceled the contract, I was told that I would still pay the full amount for April, but that I would only be liable for 7 days of May, which is when the contract end date is. I received the Invoice for end of May, and it is the full amount again. I called the call center twice to resolve this, and nobody was able to assist me, after the 3rd attempt I was able to speak to a call center manager, I explained to him that I want the recordings of my calls and that I am not willing to pay for the full month of May as I gave due notice, I am appalled by the condescending way this man thought he can speak to me, asking me if I know how to read contracts and that Vodacom will NEVER only let me pay up to contract end, saying that I will pay for the full month. He said he will listen to the call recordings himself, after I requested numerous times that I am within my right to receive these recordings, he has still not sent them to me, called me back or copied me in any dispute correspondence. I have call times and dates, with reference numbers, and still Vodacom refuses to give me the recordings.