Mr Kairau was pushed to the ground, where he was kicked and punched about the upper body and face. One of the offenders snatched the cell phone from him, while another tried to steal the van.
"I was trying to fend them off, I managed to get my keys out of the ignition and get hold of the RT [radio-telephone]," he said.
"They were hitting me from behind as I called for help. The other taxi drivers started saying, "who is this? where are you? That's when the young guys took off down the road."
Another taxi driver called emergency services, who arrived on the scene soon afterwards.
Mr Kairau spent Saturday night in Hawke's Bay Hospital with a fractured jaw, black eye, tender ribs, swelling and bruises and abrasions to his face and body.
"I am on a soft diet because one side of my jaw is broken," he said.
After being released from hospital at noon on Sunday, he was back at work that evening.
"I didn't want to sit around and feel sorry for myself, you have got to get back on the horse," he said.
In his nine years as a taxi driver - one in Christchurch and the rest in Hawke's Bay, Mr Kairau had never been attacked or abused and experienced only "runners" who took off without paying about six times.
"It's not that common to get runners, but to get really beaten up that's unusual for here."
All four of the offenders were apprehended by police shortly after the attack and had been referred to Youth Aid in Napier.
Hastings Senior Sergeant Luke Shadbolt said a 16-year-old "main offender" was charged in relation to the bashing and was set to appear in Youth Court.
"This is the first incident of this kind I have heard of in a while," Mr Shadbolt said. "But it's been a hazard for taxi drivers for years."
In-car cameras and distress buttons installed in many cabs were a great deterrent, however, it was up to drivers to determine if individuals had the money to pay the fare before taking them anywhere, he said.
