They wanted a counsellor to visit Brad in his home on a regular basis. Instead they were only offered phone numbers to ring counsellors.
"He went to a psychiatrist a little while before he died. I don't know his name, but Brad got a full written report," Mrs Milne told the Bay of Plenty Times Weekend.
"His GP and the psychiatrist referred him to a psychologist who was going to talk Brad through everything. He was waiting for a psychologist appointment, but it came after he passed away."
They have lodged their complaint and are awaiting a decision. They are also considering a formal complaint to the New Zealand Medical Association.
"Brad's passing has affected the whole family, left us with a hollow feeling," Mr Milne said.
"We are not angry, just frustrated. Organisations failed Brad, they should keep in touch with these people, not leave them to their own devices.
"He religiously took his prescribed medications. Medications react differently with everyone."
The Milnes realised how sick their son was when he couldn't get out of bed while working as a sharemilker in Tokoroa in 2001.
"We took him back to our place for three or four days to help him pull out of it with the family's help," Mr Milne said.
In 2007, when Mr and Mrs Milne were in France for the Rugby World Cup, they got a call from Brad, who was now sharemilking down south, to let them know he wasn't coping.
"We got a friend to go down and see him," Mr Milne said. "He stayed with him for two weeks and helped him run the farm.
"He knew Brad from a little kid and was shocked at what he found. He didn't want to go out or do simple tasks."
Brad and his fiancee Sarah moved back to Tauranga in 2007, bought an avocado orchard at Te Puna and a lawn mowing business in Waihi to supplement their income, as there was no crop from the orchard.
In 2009, the couple had a son, Cole, sold their orchard and moved to Bethlehem. They had another son, Mason, in April.
Not long before Brad died, he Young Tauranga father's family demand answers
We got a friend to go down and see him. He was shocked at what he found.Colin MilneObituary, A14called his mother and told her "I need some help".
"Sarah was at work and I said, 'I'll come around'," Mrs Milne said.
"He had a phone book open at the mental health page. I thought 'I'll make him a coffee and phone the doctor'. Brad was clearly having a low episode.
"He wasn't violent, just frustrated with feeling the way he was. He was in a bad way.
"I didn't feel threatened. He was calm. I asked the nurse if I could have the mental health crisis phone numbers. Brad rang one of those numbers," Mrs Milne said.
Mr Milne said: "Brad was constantly fighting a war battling depression and though he fought so many battles and won, he was finally overrun by the terrible illness.
"I can remember asking if he was contemplating suicide, his reply was 'no, but I can see why people do'."
He spent the last afternoon before Brad was admitted to intensive care walking with him along the Mount Maunganui beach on a beautiful sunny day, making small talk to keep him occupied, having a heart-to-heart and encouraging him. "He told me 'I can't do this any more'," Mr Milne said.
He said Brad was constantly researching the causes and cures for depression, trying to understand and help himself, which became more desperate in recent times.
The Thursday before he died Brad went to his GP who could make an appointment with a psychologist in a week, Mr Milne said.
In the last week of his life, Brad emailed and paid a specialist on the internet to see if he could get some help.
Mrs Milne said Brad found a site people can go to for specialist help and she thinks it is somewhere overseas. She said he had a foreign name but does not know the name of the specialist.
"It's an email of a man desperate to be well, tired of the constant battle to be normal," Mr Milne said.
It outlines what he has gone through over the years, his various diagnoses, that he is at his wits' end, has given up any real hope of being generally happy and that he has been referred to a psychologist. Brad wrote: "It's just a big merry-go-round in search for help. The only things keeping me going are my infant, toddler and fiancee. She is very understanding."
The Milnes are waiting for a full coroner's report.
The Mental Health Foundation says as many as one in five New Zealanders have experienced a mental health disorder within the past year, and having more than one disorder is also common.
The most common combination of disorders is anxiety and mood disorders. Having more than one mental health disorder is linked with suicidal behaviours, such as suicide attempts, and increased mental health service use.
People with a mental health disorder are more likely to be physically unwell and the reverse is true.