Nedbank NOT acting in best interest of clients.

I am willing to pay R1500 per month towards my credit card debt with Nedbank. The money will cover the interest and a little bit of the capital. Yet Nedbank refuse to accept the offer and is asking for R4500 per month. I can hardly afford R1500. This means I am rather going to move the money to other debt as Nedbank is going to hand me over in any case.