Losing Quality Prime Customers

An F&I at Barons Bruma (VW) app**** for my vehicle finance for a vehicle that I am supposed to collect on Friday, 30 October 2015. I have been an MFC Customer for the past 6 years, even though I am a Private Bank client of Standard Bank. I have been able to obtain a prime interest rate on all my previous vehicles with MFC, until today when I was declined by Nedbank but approved by all the other banks?? How is this possible if: my credit scoring is tops, I have a higher income pa then I had last year and I'm applying for a car that will be R20 000 more then the vehicle finance I got from MFC last year? I'm sorry to say that I will take my business away from Nedbank, even though I considered moving my whole personal and business account to them.