Sorry to hear about your crash - and the outcome of the garage report.
Things soon add up though - isn't it something like if the cost of the repairs exceed half the value of the car its classed as a write-off?
I know I had a bump in mine, and it needed: Bumper, bonnet, new wing, two new lights & two new lights and the cost was around £2500.
then factor in the cost of recovery and what it will cost them to issue beany with a Hire car et all
have the inner wings and chassis legs been compromised?