Disability groups are accusing the Health Ministry of being mean-spirited and tight-fisted in its efforts to claw back money it gave out as a result of the pay equity settlement.
About 20,000 staff in the disability sector were included in the historic $2 billion deal that came into force in July.
Since then some employers have been overpaid but argue they should be able to keep the money.
Under the pay equity deal, care and support workers got a 21 percent wage increase.
To help make life easier for employers the ministry decided to pay the money in advance for this financial year to ensure disability services had a buffer of cash on hand to pay the new rates.
But the funding included a 2.2 percent annual inflation adjustment, which some providers have since been paid again in their new 12 monthly government contracts.
The ministry now wants to recoup the double payments by making a one off funding cut.
Disability Support Network chief executive Garth Bennie said he was furious.
He said employers should be able to keep the sorely needed money.
"There's the fact that services are only partially funded. There are other costs of the pay equity settlement that are not accounted for at all, which providers are having to pick up. In that broader picture, the attempt by the ministry to claim back the 2.2 percent issue, seems very mean-spirited to us and it's a rather cruel irony," he said.
Dr Bennie said communication from the ministry has been chaotic and providers were struggling to understand why they should give the money back.
Officials haven't recognised the huge flow costs from the settlement.
"If your support workers wage goes up then the relativity between that and their supervisors is reduced, and in some cases has been eliminated, and so providers have had to respond to that," he said.
"There are extra training costs now because the qualifications are linked to the pay that support workers get, some contribution was made to that but its not meeting anywhere near all the costs.
"Leave costs were calculated at five days sick leave, which is the statutory minimum. Many of our providers are locked into collective agreements where there is 10 days sick leave.
"All these little things add up to a huge and significant extra cost for providers, that they're having to assume because of the pay equity implementation," he said.
The ministry wouldn't be interviewed but in a statement said employers were told in June that some of the advance would have to be paid back.
The PSA represents many of the support workers. The union's national secretary Erin Polaczuk said she could understand the sector's frustration and the ministry is sending mixed messages about how important equal pay is.
"On the one hand we've got agreement in the sector that women are worth 100 percent and indeed the men in the sector who have benefited from this pay increase. And yet on the other hand there seems to be a reluctance to meet the costs of that fully," she said.
Dr Bennie said the the ministry had made one concession by asking for six months of overpayment rather than the full year it originally wanted.
He was expecting an official letter shortly explaining the changes.
Meanwhile, the ministry said it wouldn't know how much money is involved until the end this month.