debt Issues and unwilling to accept payment I can offer

I tried to make an arrangement two years ago with paying off my credit card. FNB suggested the debt goes into budget so there is a monthly repayment t - never telling me HOW MUCH I’m going to have to repay, and also refused to close my credit card. I tried again now to make an arrangement to pay it off in a monthly sum and they were unwilling to accept what I can afford. It’s their fault in the first place hat the account has such a high repayment rate. Absa wants R1500 less per month. For R40000 FNB is requiring me to pay R2000 over sixty months to pay back. This is ****************. I can only afford R50 and since it’s FNB’s bad advice that caused this In the first place I think they should rectify it. I’m still nowhere and have been trying to resolve this issue. Now it’s at the point where they aren’t even responding to my emails anymore. Please can someone help!!!!!