V50 Brakes : hand brake issue

[alexv50]

recently bought my second volvo v50 r design 2.0d its know done 10500 miles. parked it up on a slope then after 15 mins the car rolled down the hill into a horsebox!! volvo have said there is nothing wrong with the car after running tests for 1 week although when i got back in the bent car they had made an adjustment to the handbrake ( it was much tighter and more efficent to use ) they have offered to pay insurance excess of 300 quid. i feel pretty hard done buy espeically as my last v50 went in for a handbrake upgrade. also know one would answer why it took 15 mins for car to move or why they felt it necessary to make an adjustment to the handebrake after the car had apparantley passed the relevant tests!! has any one else had handbrake issues on a 08 plate or new car____ volvo reckon know problems reported as yet..