Telkom Billing Department!!

This is regarding the terrible service I have been receiving from the Telkom billing department. For the past 2 years or so, I have been paying my monthly invoices via EFT. When I took out a mobile upgrade in July that's when problems started. I EFT around 23/24/25th since August, but they keep on trying to debit on the last day of the month. Why attempt a debit order when I have already paid what was invoiced? On the SMSs that I receive it says please ignore if already paid, so ignore it? Sure, its a system that determines these payments, but now I'm in arrears of R1800.00 because of the charges?? I have emailed the billing departments for the past 3 weeks now and I have sent all the proof of payments and explained in detail the situation, but all I get is the same response from different consultants - "please provide us with your account number." I called 081180 yesterday and spoke to one of the consultants for at least 20mins with which most of the time I was placed on hold, then he cut me off - I called back and spoke to a lady - same thing - she cut me off! I am afraid I have lost all energy to argue about this as I have been chasing up everyday about this matter, I am willing to change service providers now even though I have been a loyal Telkom customer for close to 8 years. I am NOT going to pay that arrears amount at all because they try to debit and find nothing in my account - THEY SHOULD CHECK IF EFTs HAVE BEEN DONE FIRST otherwise they should change the way their system works! I hope this gets out to the right people to action because the lower level staff wont do anything. I have all my POPs - I need that arrear amount to either VANISH or BE CREDITED. I have advised them so many times that this service is for my remote work job and it helps me when there is load shedding. I NEED THIS RESOLVED AND REACTIVATE MY SERVICE!!!