Vehicle approved with higher interest rate

I app**** for a vehicle finance and i am not happy with the interest rate i was given, i would like to negotiate for a better rate but i don't know who to speak to, the reason i want to be financed by MFC is because i have recently switched my home loan to Nedbank , My credit card is from Nedbank and my current car is financed by MFC. so i want to move everything to Nedbank but the interest rate i was given is a bit high which make my installment to be high, so i am kindly asking MFC to reduce the interest rate to what i am currently at 10% or atleast increase the term to 84 months . PLEASE