Differential motor problem 2010 xfr

I wonder if anyone can help me out there I have a Jaguar xfr 2010 and it seems like I started getting that warning about the differential fault took it to Jaguar they told me he needs a differential motor for $1,600 my extended warranty of course does not cover this they only cover the differential so I’m wondering is there some way around this is there another wording for this part that’s covered under electrical that I just don’t understand that the warranty company is just trying to screw me out of paying this money and is this always the case because the dealer also said this might not solve the problem of that dragging when I turn the wheels to the left and the right so maybe somebody out there has had the same issue you can tell me how to solve it that would be great please let me know