Vodacom contract Complaints

my contract with Vodacom was supposed to expire on September 2021 and as early as august 2021 indicated to them that I don't intend to extend the contract, they must convert it to prepaid instead of cancelling the contract they extended it again for another two years. I've been to the branches and called in and every time there is different excuses not to cancel the contract or they just hang up in the middle of the conversation i just want this contract to be cancelled as it has expired.