Families in Wales who may have been wrongly charged care home fees could have to wait another three years before hearing whether they get a refund.
Many have already been waiting for years and are angry that the backlog of claims has still not been cleared.
Opposition parties said the Welsh government was not doing enough.
But it said some payments had already been processed and the outstanding backlog had fallen from 2,450 claims to 1,995.
Families who feel they have wrongly paid care home fees can challenge that decision.
However, if the fees date back to before April 2003, the claim needed to be lodged by the cut off point in 2009.
Powys Health Board is now responsible for looking into those historical claims for the whole of Wales, as well as more recent claims made before August 2010.
But it has a backlog of almost 2,000 cases, and it told the BBC Politics Show it could take three years to get through them.
The Waite family in Gelli, Rhondda, spent £40,000 on fees to ensure their mother Beryl received professional nursing around the clock at a care home.
Her sons are happy with the care she received, but believe it should have been free and have been trying to claim the money back since 2006.
"It was quite a big surprise actually because it meant that we had to sell my mother's house to cover the cost of keeping her there," Kenneth Waite told the BBC's Politics Show Wales.Complex cases
If Mrs Waite had received an assessment by the NHS, her lawyer said she would have been recommended for ongoing health care, which meant her place in the home would have been paid for by the health service.
But because this assessment never happened, the local authority means tested her instead, and decided that her family should pay.
Welsh Liberal Democrat health spokesperson Peter Black said the Welsh government had failed to give the issue the priority that it had promised.
"They have failed to take account of the situation many families around Wales found themselves in and they have failed to put in place systems to deal quickly with those claims that are fairly straightforward, and also to deal with the more complex cases in good time," he said.
"I just think the minister [Lesley Griffiths] needs to get a grip on this and she needs so sort it out quickly, and certainly much more quickly than the three years we're now told it's going to take to resolve all these claims."
The Welsh government said it recognised the concerns that had been raised "which is why Powys Teaching Health Board has been tasked with ensuring that a fair, consistent and equitable review of claims takes place on behalf of NHS Wales".
A spokesman said the cut off date in 2009 had resulted in a "considerable influx" of new claims.
"Without a new approach, it would have taken many years to clear the backlog," the Welsh government said.Frustrating wait
"The total number of claims received in Wales was approximately 3,500, which was reduced to 2,450 after scrutiny. Some payments have already been processed and the outstanding backlog has fallen from 2,450 to 1,995.
"Claims are being dealt in the date order that the application was made, and not by the dates of the claim period. It is envisaged all outstanding cases will be cleared within three years."
Lisa Morgan, a partner at Cardiff-based lawyers Hugh James, said it had been a frustrating wait for families.
"The longer that these cases take, the more interest is going to have to be paid and it's detrimental to the public purse," she said.
"I think also something that's very important is that this is not compensation, it's money that should never have been paid in the first place."