Cancellation of Vodacom contract impossible

My brother who lives overseas after suffering a dreadful attack on his farm (wife was ******ed) has been trying to cancel his contract for the past 8 months for a Wifi router which was supposed to end February 2020. He is being billed R770.37 a month up to present. He has written to the addresses given but they keep on deducting this amount. Can anyone tell us what to do? I am his sister and live in Salt Rock, KZN. I have been trying in vain to get this sorted but get shoved from pillar to post if I manage to get through. He is suffering from post traumatic stress and has a bullet in the back of his head, so all this is not helping. Vodacom is a disgusting company - I advise my friends NEVER TO USE it. My email address is *** and would welcome any help whatsoever.I visited the Ballito Junction branch on 18th December 2019 and spoke to Jessie who assured me that the contract ended in February 2020. Reference number then was I-***