Contact the firm's branch manager. And, send a telegram, or registered or overnight letter to the compliance department of the firm refusing the purchase. Also, follow up with a phone call to the firm's compliance department. The longer the lag time, the less substance and credibility your argument has. Take immediate action if something looks wrong.
Time is critical.
Before you make an investment, be prepared, do your homework, and don't be caught off-guard. Investigate thoroughly any potential investment before you make it, as well as the broker and securities firm that are recommending it to you. Research all materials available to you, such as a prospectus, annual report, and other offering information. Get to know the firm and the individual you are dealing with. Beware of exaggerated claims and high-pressure tactics.