State officials say a Bismarck spa that closed in October could owe customers more than $500,000 for unused gift cards.

A civil lawsuit filed by the North Dakota Attorney General's office shows that consumers of Spa D'Athena have unredeemed cards and massage packages valued between $50 and $750. Nearly 1,350 people have filed complaints.

The spa operators say the money for the gift cards was spent on business expenses and they do not to have the funds to return to customers. Assistant Attorney General Parrell Grossman says the owners were offered an opportunity to settle the complaint out of court and declined.

The suit says the spa sold gift cards through Oct. 13, two weeks before the business closed its doors.

The spa operators could not be reached for comment.