NEW YORK (AP) — The Federal Trade Commission is suing Amazon over charges that the company has not done enough to prevent children from making unauthorized in-app purchases, according to a complaint filed Thursday in federal court.

The move had been expected since last week, when Amazon said it wouldn’t settle with the FTC over the charges. Amazon said in a letter to the FTC last week that it had already refunded money to parents who complained and was prepared to go to court.