FINRA’s website has a place to file a complaint on its website. They state that before filing a complaint, the complainant should first contact the subject brokerage firm. In their own words: “Immediately question your broker about any transaction that you do not understand or did not authorize with your broker. If you are not satisfied with your broker’s response, contact the firm’s branch manager or compliance department. If you lost money or there was an unauthorized trade made in your account, you should complain in writing. Retain copies of your letter and of all other related correspondence with the brokerage firm.”