"My father's wait for an ambulance"

My father who is in his 90's was left waiting in his driveway after falling for 3 hours for an ambulance, well past mid-night on a recent, particularly cool night. The ambulance was called around 22: 00 and it came just before 02: 00. He had a broken femur, and has a heart condition. We understand the ambulance service is busy, but what to the call centre constitutes an emergency? The paramedics themselves were fantastic, and even they said he was clearly the most urgent call of the evening they had had so far that night and they should have been sent sooner. Several calls were made to the centre and yet they did not send someone out for 3 hours.