You could hit a few problems here! The hire company will (I would hope!) have insurance, but in order for them to pay, you would have to prove negligence against the driver of their car. To do this, you would have to serve civil proceedings (not a criminal prosecution) against the driver and obtain an unsatisfied judgement. As the driver is overseas, you would probably spend more money trying to do this (no doubt unsuccessfully) than the cost of the repairs. The hire car insurers may be being difficult, but they are under no obligation to pay without an unsatisfied CCJ. Sorry.