Drivers were paying an extra 70-cents a gallon.
Indiana's attorney general says carelessness at one station caused the trickle down effect. Those gas stations must now pay back those customers.
"If they bought fuel at these stations, they need to take their receipts back into the station and they'll get a credit for that excessive amount that they paid," said Steve Carter, Indiana Attorney General.
This is the first time since the terrorist attacks of 9-11 that the attorney general has forced gas stations to make good on bad pricing. In 2001, more than $32,000 was refunded.