Incorrect billing errors

In Sep i got a call that my debt order returned, i then informed the lady that they must debt the account because the funds is there. The debt should only have been for +- R660 00 i could not see that she did it so i did a transfer instead. I received a bill at the end of Oct saying i owe them R3000-00 i have been phoning to get the problem sorted and they keep on escalating my problem but it never gets sorted. <br> <br> Now i just received a bill again for R3067.00