Telkom billing system

When Telkom deducted an amount of R438.00 on my bank account, even though I didn't owe them anything my account with them was up to date. It was on the 30th January,I called telkom to ask why was this amount deducted, they said I must call after 48hours as the transaction won't reflect on their side the same day, I called them again after 48hours but still transaction was not reflecting, I had to send them my bank statement to show that Debit order went through, so only on the 17th February I was able to log a case with them, agent told me it will only take 72hours for the money to be reversed to my Bank account, but after 72hours I called then still the other agent told me they calculate 9hours per day to make 72hours, fine still on the 01 March I called telkom to ask why my money was not yet deposited into my bank account, the agent told me they still need to do more investigation that will take about 7 to 10 working days. Why so much investigation where there is proof in my bank statement showing they deducted this amount, why do I have to suffer to get my money back