Loan impossible to settle

About 5 years ago I took out a loan of about R50 000 which I paid R2400 per month. At one stage about 2 and a half years ago my husband was retrenched and I couldn’t make a payment for a few months. African Bank then came to see me to make an arrangement whereby I pay only R1200 every month. I understood that meant that I will pay off the loan over a longer period than initially agreed. However, it’s 2 and a half years later and I have not skipped a payment but when I requested a settlement quote in Feb 2018 it showed that I owed African Bank R42000. When I requested a settlement quote again on 22 June 2019 it’s now reflecting that I owe African Bank R51000? How is this possible?? I do understand that my loan will take longer to pay off due to me only paying half of the original agreed amount. However, what I don’t understand is my settlement that just keeps increasing even though I make a payment every month. So this means that I will never be able to settle my African Bank loan. It feels like I am being ****** because the more I pay the more I owe.

I did go into a African Bank branch in Midrand on 22 June 2019 and the consultant was not able to assist me. He only printed out my statement for the last 2 years where it shows that my settlement amount is just increasing.