False discount

I had a loan with old mutual and my account was handed over to fusion credit WFS.

I was owing an amount of R7000, this company approached me and offered me a discount. Month end of June I was supposed to pay to pay R200 which I couldn't pay due to having financial problems. The issue now is that today I received a call notifying me that i am owing R700, I was under the impression that I only have a balance of R200 that i need to pay on the 15th of August then after this R200 they'll give me a paid up letter.

I'm angry that the discount that they've been offering is actually a false discount and I feel like I have paid more than what I am owing. I am sorry but the only amount I am willing is R200. I have other debts as well that i need to tackle. I did not run away from my debts and I feel like you are taking advantage honestly.