The PSC recently filed a lawsuit in the U.S. Fifth Circuit Court of Appeals that alleges “inexcusable” delays in resolving its complaints against Entergy’s nuclear power plant in Mississippi is costing customers $4 million a month in just one of many open cases, The Advocate reports.

The lawsuit suggests FERC is more focused on incentivizing clean energy than resolving the PSC’s complaints against Entergy, which recently offered three states a settlement to refund hundreds of millions to resolve the issues at the nuclear plant.

That’s a problem because FERC can only grant refunds for 15 months, according to the lawsuit, which argues FERC should give the “same preference” to actions as utility rate filings that are required to be acted on within 60 days, according to the news site.

“Each day of FERC’s inaction imposes irreparable injury on consumers,” the lawsuit reads.

The Louisiana PSC, the New Orleans City Council and regulatory agencies in Mississippi and Arkansas accused Entergy of overcharging ratepayers through tax maneuvers, incentive pay for executives and through other issues at the Mississippi facility that sells wholesale power to multiple states.

The Mississippi Public Service Commission announced in June it agreed to a $300 million settlement to end the state’s part in 13 rate proceedings before FERC, finalizing a dispute that began in 2017. Entergy did not admit any wrongdoing as part of the settlement and said it’s simply trying to mitigate costs from the ongoing FERC dispute.

“Entergy has long maintained that the disputed positions regarding the taxing, financing, accounting and operating of Grand Gulf before FERC are proper, well-reasoned and in the best interest of its customers and the company. Entergy also believes Grand Gulf has provided consistent value for its customers through its operations over the years,” an Entergy statement read.

The deal uses $200 million to offset high fuel prices that the company planned to pass on to customers, and $35 million in lump sum bill credits to Entergy Mississippi customers amounting to a one-time credit of $80. Another $50 million in bill credits were also made in prior refunds as part of the FERC proceedings, according to an Entergy statement.

“That proposed refund amount would not come close to making New Orleans ratepayers whole for … years of overcollections,” the New Orleans council wrote in rejecting the $116 million settlement offer.

While FERC has yet to resolve the disputes, the Grand Gulf facility has continued to struggle with a shutdown in July, which increased Entergy’s reliance on costly natural gas to produce electricity. Entergy passes those costs on to ratepayers.

While the plant resumed operation on Aug. 9 according to Nuclear Regulatory Commission records, the plant was completely shut down from July 13 to July 31.