Unable to cancel contract with vodacom - customer care service non-existent

Took out contract with Vodacom and contract is ending the end of January 2020. I started phoning Vodacom in the second week of December 2019 already to give notice that I don't want to extent the contract and the contract must close at the end of the contract period. Been phoning different times of the day and either the line dies or I am kept holding on for minutes on end. After phoning again this week to try and get through to them I visited a Vodacom shop and they advised that the only way to stop the contract is to phone in. I tried today again endlessly and eventually got someone to answer after the 5th try. He couldn't hear me so I asked him if he could phone me back and he didn't want to. He started doing the security check and I apparently failed of which I can't understand due to me actually giving him the correct info. I asked to chat to his Manager and he ignored me and put me through to the after call rating service. I have my account infront of me and gave him all the correct info and yet I somehow failed the security check. I asked to please re-do it because something must be wrong. He said I can only try again in 24 hours!! Seriously?? How on earth do you cancel a contract with a company like Vodacom?? It really can't take 3 weeks just to get some level of customer support. Now I get through and this is the type of customer service agent I get? Now I have to wait another 24 hours and guess what, now Vodacom will say "Sorry, you didn't give enough lead time for cancellation - pay another month" I didn't battle this much to get the contract, seems now I can't even cancel it. Please Vodacom, be so kind as to show me customer service and actually asssit!!!!!!!