Mrs Crystal has found casual work but it is not enough to pay the rent and other bills and feed the family.
The whole community where they live at Onewhero, in the northern Waikato, has rallied round to donate food, grocery coupons and cash.
"We don't even know half the people. Sometimes they just turn up with an ice-cream tub full of soup," Mrs Crystal said.
The family are trapped in a no-win situation. They haven't got $8000 for air tickets back to Britain, and even if they did, they would face a six-month stand-down to get welfare there because they have been away more than two years.
The stand-down would be waived if New Zealand deports them after their visas expire on December 16, but they don't want to put the children through a process that may involve being arrested and jailed.
Mr Crystal, 49, drove petrol tankers in Britain for 20 years before being recruited to drive for Caltex in New Zealand. The family arrived on a work visa in February 2006.
Three years later, they switched to a long-term business visa to start their own business painting, removing graffiti and installing protective coating. Later they added a second business installing and maintaining amusement machines.
The two businesses were successful and, after the required five years, they were about to apply for permanent residence when tragedy struck.
"I was actually driving to a new contract when I had a seizure," Mr Crystal recalled.
"I just had to pull over. I was gone for 20 minutes. Sarah was with me and when I came to, there was an ambulance there. They took me to hospital."
Doctors took a lump the size of a golf ball out of his brain.
"Unfortunately, this left me with a large blind area on my left side and a constantly dizzy sensation, which feels like I am repeatedly free-fall skydiving," he said.
"This results in my constantly bumping into and tripping over things. My short-term memory is really terrible. I get up to do something, usually trip over something on the way, and have forgotten what it was I got up for."
He can't drive or climb ladders, and has to lie down after about an hour if he tries to work.
After the first operation, doctors gave him one year to live. Two years later, his specialist says he still has only a 20 per cent chance of surviving the next three years.
Meanwhile, Mrs Crystal kept the businesses going. "I did all the businesses, I never stopped," she said.
"Trouble really started because I worked myself so hard that in the middle of winter last year I got pneumonia. That knocked me for six or eight weeks and we got behind on our bills and everything and just sank."
They sold a van and other possessions and managed to keep going until September this year, when they applied to Work and Income. They were turned down three times until Ms Power intervened yesterday.
They have not had to pay for medical treatment and the children have been able to stay in school. But daughter Claire, 17, finishes school this month and faces international student fees of about $20,000 a year for tertiary education.
Mrs Crystal has found casual work packing olives until Christmas but brings home only about $440 a week. After $300 in rent, $40 on electricity and $80 on petrol for the 30km trip each way to work, the family have just $20 for food and other bills.
Rev Alan Rowe of the Onewhero Anglican Church said news of the family's plight spread quickly and many people stepped in to help.
The community paid the fees for Claire and 15-year-old Max to sit NCEA exams and raised $550 for the family's appeal on their residence application.
Waikato MP Lindsay Tisch visited the family at their home and helped prepare the appeal.
"They have done everything right but circumstances have moved against them," he said.
But Immigration NZ acting general manager Bruce Burrows said their application for residence was rejected because Mr Crystal was no longer actively in business and was "likely to impose significant cost or demands on New Zealand's health services".
Donations
Donations for the Crystals can be sent c/o Rev Alan Rowe, St Stephen's Church, PO Box 64, Tuakau, or paid into an account Mr Rowe has set up at the ASB in Pukekohe: 123023074765300.