MiWay Insurance refuses to co continue with claim after an accident

My mother recently had an accident. She did all the necessary requirements for the claim, however the other party involved in the accident refused to go to the police station and make a statement. Miway was meant to send an assessor. After a week of no communication, she contacted them asking about the assessor only to be told that her claim will not move unless the other driver goes and makes a statement. How is my mother then supposed to make this guy go make a statement so that Miway can continue with the claim?