Bogus upgrade sold to elderly gentleman who doesnt understand technology

My 81 year old dad (who has had a stroke andwho cannot process complicated information) was called and asked if he wanted to upgrade his contract. He was assured that it would not cost him more. He received a sim card (that doesn't work) and no new phone. We suspect that he was put on a data contract (he doesn't have access to wifi or know how to use a smart phone). His monthly contribution has now more than doubled (he is a pensioner and can barely afford the debits he has). My brother tried calling Vidacom with my dad next to him, (he did provide I'd number) to find out what is going on but vodacom would not help him as he could not pass the security questions because he has forgotten them (the stroke! ). We are unable to resolve this as my dad lacks the cognitive capacity to speak to customer services and they wont speak to my brother. Taking him into a vodacom walk in centre is difficult due to his frail health. Please can someone contact my brother to sort this out and explain what contract he is on. Please consider cancelling the upgrade as he dis not understand the sales call, cant use the product nor afford this monthly debit.