ATLANTIC CITY, N.J. (AP) — Online gambling company bet365 must refund more than a half-million dollars to customers who won bets, but were paid less than they were entitled to when the company unilaterally changed the odds when making the payouts, state gambling regulators said.

The New Jersey Division of Gaming Enforcement ordered the British company to refund more than $519,000 to 199 customers who were shorted on the payouts they received after winning their bets.

The company told New Jersey regulators they changed the odds due to “obvious error.”

But the acting head of the enforcement division noted that any company wanting to void or alter a payout must seek approval from the agency before doing so. She called bet365’s actions “a prolonged and unacceptable course of conduct.”

“These types of multiple and serious violations cannot be tolerated in the New Jersey gaming regulatory system,” Mary Jo Flaherty, interim director of the enforcement division, wrote in a July 22 letter to the company. “No further such violations relating to the unilateral voiding of wagers will be tolerated.”

The company did not contest the order, which was made public Friday. It declined to comment through a spokesperson.

According to the state, bet365 unilaterally changed the odds on events upon which people had already bet and won between 2020 and 2023, paying them less than they were entitled to under the original posted odds.

The events ranged from a Christmas Day table tennis match in 2020 to NFL, college basketball, mixed martial arts and the Masters golf tournament in ensuing years.

In each case, customers placed a bet relying on a particular odds calculation but were paid based on a less favorable odds calculation.

The state said bet365 claimed it had the right to change those odds “because they were posted in an obvious error.” But the state said that as an authorized sports betting provider in New Jersey, bet365 should have been aware of the requirement to get approval from the gambling enforcement division before voiding or altering wagers.

Flaherty called those failings “problematic” indications of bet365’s business ability to conduct online gambling operations, and of the integrity and reliability of its operating systems.

The company also was ordered to submit a detailed report on efforts to identify and correct any failures of internal software systems, its human errors, and steps to ensure the accuracy of its data feeds.