Telkom -please can you sort out your mistaken invoice?

Telkom send me a bill for R12000 and something on the 7th of June. I have called them numerous times to rectify my invoice as I did not ask to pay off my devices in one settlement! I have a two year contract and want to pay the devices off over the two years as my contract with them. Obviously nothing was done to rectify my invoice and the debit order went off at the end of June. I had to reverse the debit order through my bank as I do not have R12000 budgeted for a phone bill. I called Telkom's customer care number to let them know that I have done this and they should please send the amended invoice for me to pay the correct amount. They obviously did not do this, and at the end of July my account was blocked / locked. I then phoned the very efficient and competent customer care line again and obviously a case was logged but nothing has been done, that was a week ago, and still there is no solution to the problem. So no-one in our family has a phone that works for more than a week now, and Telkom still has not been able to rectify the mistake they've made on my invoice. I have no idea how to get to anyone in Telkom that can help me sort this out, as all anyone in the entire company can do is, wait for it: "LOG A CASE". - which means absolutely nothing.

please is there anyone out there that can actually help me sort this out???