So sorry to hear about your poor Bongo
I read elsewhere that it may be written off.

I hope that the insurance company of the driver who parked behind that caused the problem will pay the full value and that you won't have to pay any excess. If his/her insurance company doesn't know much about Bongos they may well undervalue it hugely. Mine did when I was broadsided by someone who's details I didn't get before he departed, and they tried to make out mine was worth 1/6th of its true value (they just based their estimates on an average car of the same age).
It's even more frustrating when the damage is absolutely no fault of our own. Stick to your guns.