The National Disability Insurance Agency (NDIA) has apologised to two families who had been kept in the dark for months over access to missing funding to care for their children with complex disabilities.

Key points: Chloe Tomlinson, 23, requires around-the-clock care due to a rare brain condition

Chloe Tomlinson, 23, requires around-the-clock care due to a rare brain condition Her family is one of many who have waited months for a verdict on funding appeals

Her family is one of many who have waited months for a verdict on funding appeals The NDIA has apologised to two families "for any delays they have experienced"

In one of the cases, the mother of a young woman living with a rare brain condition had made three unsuccessful appeals under the National Disability Insurance Scheme (NDIS) and had been waiting months for the outcome of the fourth.

Nadine Tomlinson's daughter Chloe requires 24-hour care and has developed various other conditions such as chronic pain, bouts of violence and disorientation.

The 23-year-old has Chiari malformation — a collapse of the back of the brain — and a spinal cord disorder called syringomyelia.

Chloe can no longer live in the same house as her mother and relationships with some of her family members have deteriorated as her condition has worsened in recent years.

'I was getting desperate'

Chloe Tomlinson, who suffers from a rare brain condition, as a young girl. ( Supplied: Nadine Tomlinson )

Chloe was first given access to the NDIS in 2018 but, by Ms Tomlinson's calculations, was only given roughly half the funds she needed to pay for support workers to look after her around the clock.

As a result, Ms Tomlinson, who is unable to work while she manages her daughter's funding and care, was forced to pay her support workers far below the award rate.

After three unsuccessful appeals, she lodged a fourth appeal in August.

At that point, Ms Tomlinson had just about run out of options and was considering moving out of her home south of Perth and looking for a cheaper rental property.

"I'm very scared about the future because I need to work, but I can't, at the same time, fight the NDIS, fight Chloe, fight the doctors, fight the Government," she said.

Chloe Tomlinson has struggled to get NDIS funding. ( ABC News )

In early November, after two and a half years of appeals, the NDIA finally decided to provide around $370,000 to fund the remainder of Chloe's current plan.

"I was getting desperate to try to find the help I needed," Ms Tomlinson said.

"So I mentioned that the ABC was doing a story on my battles with the NDIS.

"I don't know if that influenced it, [but] I feel like I am finally listened to."

The NDIA didn't provide an explanation about why it finally decided to provide significantly more funding after three failed appeals.

"It's been a long, long time that we've been doing this and I can finally pay [Chloe's support workers] according to what they should be paid," Ms Tomlinson said.

It was not long after she told an NDIS staff member that 7.30 was making enquiries about her case, that she was told her fourth appeal had been successful.

Selling the family home

Each of Melissa Rowles's three sons has complex disabilities and caring needs. ( ABC News )

Melissa Rowles has three sons with various disabilities, including autism and cerebral palsy.

She manages her sons' funding and care herself, which means she is unable to work.

After being left with a shortfall of what she believed to be almost $20,000 in NDIS funding, she and her husband decided to sell their family home and move into rental accommodation to help pay for the care their sons need.

"The balancing act between the financial responsibilities … and then the care the boys require is a tightrope," Ms Rowles told 7.30.

"I've made phone calls to NDIS to see where we're at, and they can only tell me that it's been assigned."

In a statement, a spokesperson for the NDIA said the agency apologised to Ms Tomlinson's and Ms Rowles's family "for any delays they have experienced".

"[The NDIA] will continue to work with both families to ensure they have the appropriate funding for their disability-related support needs," a spokesperson said.

"Where a participant's experience has not lived up to expectations, the agency is committed to working with them to address concerns."

Funding review delays

Melissa Rowles and her family have sold their home to help them cover for the delay in getting NDIS funding. ( ABC News )

The Commonwealth Ombudsman has found that the NDIS has struggled with the blowouts of appeal timeframes, sometimes for as long as nine months.

In an investigation it found in February 2018 the NDIA had roughly 8,100 reviews underway, with 620 new review requests each week.

"We consider more can and should be done to ensure administrative drift or under-resourcing does not prevent participants from readily exercising their review rights," the report read.

As of the end of October this year, the agency employed roughly 400 staff in its complaints and review section, with 52 more to be employed over the summer.

Problems with the NDIS are well documented nationally, but in Western Australia — partly due to its size — there are unique challenges.

The Goldfields region around Kalgoorlie, for example, has previously suffered critical staff shortages and struggled to attract disability organisations to become providers because it is financially unviable to do so.

"The NDIS has not dealt adequately with market failure," Robert Hicks, then-chief executive of GIFSA, the region's largest disability services provider, said in May.

"The Government at the end of the day may well have to be the provider of last resort."

Price increases for remote and regional NDIS participants were announced in June by the minister responsible for the NDIS, Stuart Robert.

"The NDIA will continue to monitor remote and very remote markets across Australia and, where necessary, intervene," he said at the time.

In an address to the National Press Club earlier this month, Mr Robert announced further changes to the scheme, which he said was "not always living up to high expectations".

Mr Robert was approached for comment on Ms Tomlinson's and Ms Rowles's cases but referred questions to the NDIA.