Impossible Cancellation with notice

My cellphone contract was due to end on 23 August 2021. I went into Vodaworld to try and cancel it and move it onto prepaid in May 2021 since I got notifications that I could upgrade. I was told that there is too much time left I should come back later. I was not informed of any notice period since the contract has clear start and end dates. I again went into the branch in July 2021 to cancel the contract. I was given a number " ***" to call. I told them I was worried about any notice period. I was told that this is not an issue. I tried calling the number a few times but after 5 minutes of trying to get through no answer. I finally got thru today and low and behold they told me that I had not given them enough notice. blood suckers. Now apparently the billing is in arrears so next debit order will be in October 2021. Got told this after 10 minutes of attempted upselling to try and keep me on contract. I explained to them that I lost my job last year and hence I wanted to go onto prepaid. In future I'm rather gonna stay on prepaid. During my contract period I continuously had to buy data and airtime. the insurance was useful but still has an excess fee. sis Vodacom.