Cancelation

Been trying to cancel the contract since November 2023. Nothing has been done the money is still being deducted every month. I have been trying to do this on behalf of a parent as he works 7-7 everyday and is unable to call himself. Was told to get a letter (granting permission for me to do the necessary for him) from the Vodacom store but when i went to 2 different branches the 1 knew nothing about a letter and the other said we must get a lawyer to draw up the letter. So sick of this running around, customer service is disgusting. How hard is it to just cancel contracts. They are Pathetic!