Unreasonable Charge - Debit Order Rejection Fee

Late payment of my salary into my bank account resulted in Telkom's debit order for R199.00 being returned unpaid, which I was not aware of. Telkom subsequently did another debit order and included an amount of R200.94 for a debit order rejection fee, which is ridiculous. According to me I never agreed on this exorbitant fee in a contract, website or in any other way or form. I am contemplating ending the contract, because this conduct is shocking.