Request for cancelling expired contract

I'm hereby raising complaint on behalf of my mother, who is still receiving airtime contracts, already expired. She tried to communicate with the shop about cancellation. They said she must raise this issue to Vodacom. Then, I assisted her to call Vodacom Contract cancellation for more than 4th times, nothing they did to cancel this contract. Her names are: Aifheli Lizbeth Mulondo. ID: ***. Her phone number: [072] ***.