Cancelling a telkom contract is a nightmare!!!

Cancelling a contract with Telkom is a NIGHTMARE!! Last year April the contract was ending. My husband went directly to a telkom store to cancel the contract as we would not need the data anymore. He was advised that to cancel, he needs to send an email to a specific department to complete the request, which he did. The next month, they debited money. And the following month they did, which my husband started reversing. He kept calling telkom to ask why they still taking money when he cancelled a 2 year paid up contract. They asked for the emails which he forwarded to them. Now this year, debt collecting agency is calling to request this money and they have placed a default under my husbands profile!!!! What does one do in this situation??? Useless useless company!!