06 mazda 3 rear ended fighting insurance
 

well it didn't help that the person who rear ended my mazda 3 and pushed it from a stand still into the back of the vehicle in front of me. Now to add to it she had no insurance, my uninsured coverage is covering it through Farmers insurance, but now i am having to fight with them over use of oem parts. The body shop helped with attaining the oem bumper replacements. However one other item was damaged, the fuel sending unit which like all modern cars is an all in one unit including the fuel pump. They are wanting me to pay for half of the cost of the part since they can't purchase the sending unit separate and its only available oem mazda. I am continuing to fight with them over this, as they continue to say that its not probable that the impact caused the damage. I was simply like well why else did it fail immediately after impact, the car has 92k miles and no failures or any issues. All service is kept up and they still blame the reason they're only willing to pay partially is simply due to the item being a wear and tear item, in which i said the pump works find, the sending unit is what is not working. Any suggestions here?