Forcing costumers to upgrade

Vodacom contracts abuse the elderly by forcing them to commit on contracts they can't pay, my moms contract was due to end in August 2022 so July 2022 we called so that it can be canceled and insisted on talking to my mom who told them that she wants her contract terminated but they decided to upgrade come August we call again but they still wanted to talk to her and refused to end her contract, now she has this huge amount of money she can't pay and a blocked phone which she had already paid for.