********* reduction charges Telkom mobile

I have a wifi router with telkom. Contract is R150 a month for 10gb of data. On the 30th November a debit order failed. When I called the contact center it was told a double amount will be taken next month. December no debit order went off so I made a EFT payment. Now my bill for January shows a reduction fee of R202. 84 on top of my line rental if R140. I called and spoke to a agent that tells me this is a reduction fee because of a failed debit order. This amount is more than my contract worth on a monthly basis. The bank already charge fees if a debit fails so how can my phone service provider charge me a fee of more than my contract worth? Also this is a charge that telkom decided on which means a customer needs to be made aware of. It is ********* to charge customers fees and not advise them about it. When you sell someone a contract it needs to state what the customer will be charged for. This is a hidden fee and completely ********. I want this resolved and this hidden fee removed from my account.