Nedbank won't change incorrect installment amount.

Having issues with nedbank, I lost my job and my credit card went into arrears, I managed to find another job but not before my account was handed over. I am currently paying my nedbank card off. So i did an inquiry on my name to see what my statis is. According to the credit system on my nedbank debt. They have placed it as an installment of R72 000. So according to them I am paying 72000 rand a month from my salary. Where as i am Not, I did do an inquiry and they say that its there policy. I explained to them that I have inquired about a consolidation loan that will actually help me pay them and all my area accounts. But the way they have placed it on the system its affecting my affordability. I asked can they please change it the the amount I'm actually paying them. They refused and they said they cant do that. Yet when I spoke to the transunion they said it's something they do alot to prevent you from getting credit. Hich I do understand as you need to pay them first before you open more accounts. I'm trying to make a plan to pay the debt I am owing them and clear my name in the fast and most effective way and the refuse to budge. They really dont seem to be interested In getting there money in bulk. Or even try to assist to accommodate me in trying to get the money to pay them, the loan I app**** for was approved but because of affordability I cant get the amount need. I've worked it out and it would take alot less time and monthly installment amount to do this, and every one wins all my debts are paid and I get a cheaper monthly installment and everyone gets there money paid. Normally when you apply for a consolidation loan they require a settlement letter and banks details so that they can pay these accounts before you get any loan money, so they guaranteed to get there money yet they not willing to change on there system the incorrect installment amount that I am actually paying. All I am asking them to do is put the honest amount I am paying nothing more. Along with that I have a credit card with fnb aswel with the same credit limit and the same amount used when I lost my job. I am paying both off and yet my nedbank credit card is almost double what my fnb is. Same debt same type of card, (credit card) same period of time on none payment but yet I owe nedbank twice as much as fnb???? Which I didn't even inquire about I just want to settle this account and clear my name. Circumstances has put me hear not like i never paid the account on purpose. This change of installment is well with in there rights and power to do as per transunion. I dont understand why they would deprive them selves from getting there money.