10% discount to settle account with consoildation

I arranged with another institution to assist in consolidating my debts. When I spoke to Nedbank they told me they cannot remove all the interest accumulated against the account, they can only give me 10% discount. They even mentioned my contract has expired and this is the reason for only allowing 10%. It does not make sense. Contract expired and I still need to pay them. This contract was initiated 2010. They never sent me a summons or legal documents and even the assurance which I also added against this account, which is false security,if you loose your job or underwent retrenchment never agreed to pay the amount when I got retrenched without payment. They only paid R12000. I have investigated all options to assist with Debt review and got advice of Credit Matters in Cape Town told me that these companies should reduce their costs in almost 50% and or consider supporting the clients that are still trying to pay or settle their accounts, but this is not happening. To give you an idea, the loan was R135000, with interest accumulated to R178215 and now with the consolidation, I still have to pay R160393. This is ridiculous.