MFC bamboozling me! I refuse to pay for your mistakes. Fix it!

MFC IS THE WORST!!! MFC....what putrid experience. Customer service is at its worst. My initial agreement was to pay a higher monthly instalment because I don't want a residual. First contract offer was perfect with no residual and a 9% interest. According to them the offer was a mistake as the interest was too low. Now no one can find that initial agreement ive signed. All they have loaded on their system are the 2 subsequent offers they offered me. After more than 12 months and numerous calls no One has been able to advise why I am paying a higher premium and why they've add a R71000 residual to my vehicle finance. I would like a response and i want this resolved asap. Managers/ team leaders and call centre staff promise to return my calls with some semblance of an explanation or resolution but up until today nothing. I am super frustrated and dissapointed. Never use mfc EVER! WHY AM I PAYING FOR YOUR MISTAKES!!!! OR is this your way of getting back at me for offering me a good interest rate "mistakenly" in the first instance????? Id like a reference number and a copy of my original contract which is what is need for the ombudsmen. And please don't insult me the offering stating interest and my signature is on separate pages. ALL I ASK IS THAT YOU, MFC, HONOUR OUR INITIAL AGREEMENT. THANK YOU!