Vodacom contract complaint

On behalf of my mother,she is currently disabled She has a vodacom contract,and she paid it off,I've been trying to cancel the contract,I submitted my ID,mom's ID and a letter stating that she is disabled

I went to vodacom last month 27th November ,and I was told that a reference number will be sent,and I should call vodacom again,I am still waiting for a reference number, I visited vodacom store at Carnival Mall three times till to day I haven't received any feedback,but they still debting the money from my mom's account from whole of 2021 although contract has expired.