Insurance is who fights for you (in theory) in cases like this. Without insurance, you're on your own. You chose to take that risk. You'll have to argue this in the courts now, there's no other way if the city doesn't want to pay out. I don't blame them either, they know you don't have insurance, so they assume they can save money by not paying out the full amount. More often than not, they probably get away with it since court takes both time and money. That's part of the reason why it's important to carry insurance.