misleading

so our salary goes in late and unfortunately telkom did not get their instalment on the 25th. i than personally go to a telkom shop and inform them. they tell me i should deposit the money because they wont debit again. i pay the installment via eft the next day my account gets debited again by telkom. i receive my statement and my bill comes to R616 including a rejection fee. who in their right mind charges so much for a rejection fee even more than my own bank for a debit order that bounced. i was never informed about this when i went to telkom. i am so upset i just want to cancel this poor service contract.