Vodacom / VVM - picking on pensioners

1st Vodacom and then VVM have for months now been claiming that my mother owes them money. Each time that they had contacted her she had requested a statement of the amount they are claiming she owes them to no avail. Months later she finally received an email last week from VVM with a Vodacom statement, which in my opinion doesn't even look like the standard Vodacom statement. Keep in mind, my mother has never before had a contract in her name with Vodacom. VVM states that she got the contract in April 2022, which she never did. She is a pensioner, and has a prepaid sim with Vodacom. She does not have the financial means to open a contract with Vodacom. We have requested that they send a signed contract to her where she entered into the agreement with Vodacom. Now they want id copies and signatures etc from her. In my opinion it is up to Vodacom or VVM to prove that she had entered into this supposed contract and not the other way around. As stated, she is a pensioner and does not have the means to be driving around to get all the information required just because somebody else messed up.