What are you doing Standard Bank??!

Due to ongoing medical expenses I had to go under debt review in 2013. The amount I owed Standard Bank on a revolving credit account was just over R 21 000. I have been paying the amount that was made a court order for more than 7 years, and have paid over R 37 000 already, but they now claim I owe them another R27 000! This changed literally a month ago, when I only had a couple of thousand rand left to pay. How can they make me pay R 65 500 on an outstanding amount of R21 000??? I have sent emails, but just get automated responses. I have phoned, but don't have airtime to hold on for over 15 minutes each time, and STILL can't speak to anyone! WHAT are you DOING Standard Bank??? I am chronically ill and have suffered SO much to pay off this account!! Now THIS!!