Unexplainable Invoices

My Mother has been trying to cancel the contract with Vodacom for over 3 months and every month they keep on sending her invoices that require her to make payment. This company is ****ing older people with their constant unexplainable invoices. We have called numerous time asking them to cancel the contract as the 24 month of the contract has ended and to this day my mother is still receiving invoices, while not receiving any airtime or data from them.

This company is problematic honestly.