BAD service with closing vehicle file

I am disappointed in the manner ABSA is treating me. I have sold my vehicle through their FASTBUY and I was given a discount on the shortfall but that discount has not been app**** and I am told to wait for a month , I have the shortfall and I want to settle this and move on. To make things worse I am told by sms that I defaulted from my debt review arrangement and I never did that. I demand this sorted out asap and this file closed .