Worst customer service and failed to disclose important information

I requested a cancelation of a data sim card contract and was told it was cancelled, but the request was not sent to the billing department by their consultant after cancelling hence the debit order kept on going off from my account. A request was sent to Telkom's billing department and the case number ***4 was closed without refunding my R301. Called Telkom again to follow up and spoke to Zeenath (manager) who told me that a reversed debit order at Telkom costs R201 2 times more than what my installment was supposed to be of R99. I have never heard of such, no documents were sent to me stating that, and that was not disclosed when i took the contract otherwise i wouldn't have gone through with-it. Telkom is just eating people's money. Worst service provider who doesn't disclose important information to their clients because it benefits them.