Shortfall to fall off or be written off

This heartless **** of the company MFC unwittingly approved two cars under my name, and could barely manage to keep up with the installment. I called several times to ask for payment reduction, I shared proof of my income, and still they rejects my request. how can I afford two cars when all both installments equate to my salary . They are just senseless, insensitive and have no care about their customers. I decided to sell the car which still came with a shortfall of R115000 , that MFC require, that really dropping my credit and I am not able to apply for anything. I want this shortfall to fall off