The provincial government's consumer protection office says Cash Store Financial Services Inc. violated the maximum allowable charge for short-term loans — $17 for every $100 borrowed.
The office says the company charged consumers additional fees for cash cards or electronic fund transfers.
Those fees brought the total borrowing cost above the legal limit.
The government says people who paid too much at Cash Store or Instaloans outlets between Oct. 18, 2010, and Oct. 17, 2012, may be eligible for a refund.
Consumers can call the consumer protection office at 1-800-782-0067.