we have had issues with Tesco too,
ended up having to pay a third toward a bloke in a BMW who put his car on next doors garden, having tried to overtake mrs P when whe was about to make a right turn into our drive, despite indicating.
No damage to our car but Tesco 'split' the accident 70/30
was in its third year before it was finally sorted, even then we were not happy with the outcome
having an accident investigator is a waste of time as the other company hires a different one that draws a different conclusion. CSI it ain't.
neighbours as witnesses are useless as they are not deemed independant, so their accounts could not be considered
and most annoyingly if it turns out the other guys insurance company is a different division of the same parent, you are stuffed, they will do whatever they like. In my case Tesco and Renault insurance (I know on a BMW eh?) both have the same parent firm, RBS.
however some good came out of it
1 they made such a balls up, they did not penalise our no claims bonus as a goodwill gesture,
2.the BMW which lives fairly local had a dent in the other side a year later and is going rusty
3. means my dislike for BMWs and their drivers is based on fact and experience, not just a whim.
They really are as bad as is made out, deceitful, aggressive, dangerous, arrogant, dishonourable and lying motherfookers.
In summary, will not go to Tesco insurance again, I'll leave it at the bread and milk.
Good luck, I fear it will be needed.