"To file a complaint" means to officially report a problem or express dissatisfaction about something to an authority or organization, so that they can investigate or take action to resolve the issue. Full definition
I have sent her all sorts of emails, but I haven't threatened with filing a complaint with the department of real estate. (biggerpockets.com)
Some users have also filed the complaint against the trader for their missing fund but that was only the intuition that ultimately the trader will cancel the payment. (coinscage.com)
This means that you can not simply have your collaborative divorce attorney move ahead with litigation by filing a complaint for divorce. (danddfamilylaw.com)