Uber rides

I am really fed up with some Uber drivers. Most of them ask me to sit infront because they are afraid of traffic stops. However I travel alone and prefer sitting in the back seat but when I refuse to sit infront they refuse to continue the trip. One driver even went as far as to threaten to drop me on the side of the road or return to my pick up spot after being halfway to work. How is it my fault if they don't have proper permits now I'm uncomfortable on a ride I paid for. I use Uber all the time and spend a lot of money using the service. When I reported the same issue today I was told that a preferred seat is not guaranteed but the vehicle was empty and I was alone on my way to work. No man this is not right