If you receive a suspicious call on the phone and you are sure it is a scam, there are a few things that you can do to report the fraud. Your first step is recognizing whether the call is indeed a scam.
Telemarketers are only allowed to call you between 8 AM and 9 PM on your standard time schedule. If the telemarkter says he is calling within the time frame allowed, based on his time standard, you should immediately end the call and report any information you have about the company. Legitimate telemarketing companies know, understand and obey time zone rules for marketing.
If a caller asks you for any identifying information or money, again, immediately end the call and report him. Even if he sounds so convincing that you "really won this lottery and all you need to do is pay processing fees", it is a scam. Call his bluff and ask him to send it in a certified letter and then report the company to the appropriate agency.
To report fraudulent calls you must first report these calls to the FTC (Federal Trade Commission). The FTC has a way for you to handle this all online so you will not be required to sit and wait for hours on the phone to get through to a government agency. Next, many local phone service providers have a fraud hot line. You can call your local company and give them as much information as possible about the call and let them further investigate the problem. Finally, if you are the victim of a scam, contact your local authorities. You will need to go to your local police department and file a report about the incident in hopes that you can reclaim anything you lost and that the criminals will be caught.
You can help yourself avoid getting into this situation by registering with the National Do Not Call List. This list removes your phone number from telemarketing lists in the United States and serves severe penalties against those companies that do not comply. If an American company contacts you without your permission after you have entered your number into the registry you can file a complaint with the registry against the company. This does not apply to out-of-country call centers, and most of the scams that are out there do take place off of American soil.
The best way to prevent fraud is to not let yourself fall victim to the scam. And to help others, always report suspicious calls to the FTC and other regulating authorities.