Are some electrical parts unique to the chassis number?

I ask as my vehicle following some parts being fitted at an LR dealer refused to start on collection.
They state that (and these are my wifes words) That the fault is electrical. Power is going to the fuse box but not coming out. There is confusion whether its the loom or the fuse box itself but have been informed the part is built uniquely to the chassis number and needs to be ordered and I understand this could be months. I know there are specialists who can work with looms but fuse boxes??
Surely a main dealer should be able to resolve/resource this??
Can anyone throw any light on this?
vehicle is 57 plate freelander 2

The Freelander 2 has over 30 modules dotted about the vehicle. However only a few modules are VIN locked, and only a couple of those can't be configured to another vehicle.
An LR dealer should be able to work out exactly what is wrong with it, and sort it FOC if it happened while it was in their possession.
The fuse box is unlikely to be the issue, but the CJB (body module behind the fuse box) is responsible for part of the security system, along with the start control module (key dock unit), the ABS module and dashboard ECU (Ipack) where all components have to be configured to the same VIN for the vehicle to start.
However none of these modules will forget what vehicle they are in, so shouldn't just stop working, unless the place doing the work has screwed up something while working on the vehicle.

It happened in their workshop whil'st they were working on it they need to sort it...