Vehicle application approved with ridiculous interest rate when other banks are giving normal rates and conditions

I am very unhappy with fnb, i have been fnb client for the past 8 years but i don't enjoy benefits, i app**** for a vehicle and MFC approved me without deposit and gave me a reasonable interest rates, but my own bank gave me a rediculous 17 percent and on top of that they need a deposit, last year i took a home loan with a very hight rate, and now I decided to dwitch to nedbank because my own bank cannot assist me with anything, why would i stay with fnb when other banks are giving me better service? I am so disappointed in fnb and i think its time to say good bye and switch everything to nedbank