LANSING, Mich. — A Michigan gas station is facing a lawsuit for falsely advertising fuel prices.

The state attorney general’s office is suing Great Lakes Gas & Mart LLC, Orion Township, Mich., for alleged violations of the Weights and Measures Act. The law requires that if there are different unit prices for the same grade of fuel and the street sign cannot display all prices in the same size and style of lettering, then the retailer must display the highest price for that grade in the largest-size lettering.

Great Lakes Gas & Mart has two road signs that advertise the price for fuel, one for gasoline and one for diesel. Both are only able to show one price per side. The gas station offers a lower cash price and a credit price for gasoline and diesel.

In April 2016, an inspector with the Michigan Department of Agriculture and Rural Development (MDARD), which enforces the Weights and Measures Act, inspected the site and first documented that Great Lakes was advertising only the lower cash price on the street sign, according to the attorney general’s office. Not until customers pulled up to the pump did they see the higher credit price for the same grade of fuel.

MDARD reportedly documented that repeated violations happened for more than a year. While the retailer corrected the violation during one of the MDARD inspector’s visits, later inspections showed that Great Lakes continued to violate the law, according to the lawsuit.

MDARD repeatedly asked Great Lakes to fix the issue but was ignored, according to the suit. It then referred the matter to the department of the attorney general, which also sent a letter asking Great Lakes to come into compliance. Later inspections found that the retailer still did not address the issue. The lawsuit asks for civil penalties, reimbursement of MDARD’s investigation expenses and recovery of any financial benefit that Great Lakes received from violating the Weights and Measures Act.

“When a driver shops for gas, they make their buying decision based on advertised roadside prices,” said Bill Schuette, Michigan’s attorney general, in a statement. “The law is clear that when prices differ for the same grade of motor fuel, the highest price should be clearly displayed. Great Lakes continually and repeatedly deceived its customers, and now they will be held accountable for that decision.”