Remember... you don't have a chance in a fair discussion with these marketers. These people spend their entire life figuring out what will get you to buy their product and are prepared with great answers to any question of doubt you may have. You can't deal with them alone. Here is where to get help about the legitimacy of their products:

Don't think about hiring an attorney when you can get someone to investigate your complaint that is more powerful than an attorney: The Government. If the company is located in the USA they will be more afraid of the government than any attorney. If they don't play nice with the government, the government can put them out of business. Best part: it costs you nothing. Make sure you send a copy of anything you send to the government to the company in question. Here are the two main places to file. Do it not only for you, but to let others know about the practices of these organizations.

The State Attorney General's Office at - http://www.naag.org/current-attorneys-general.php

The U.S. Federal Trade Commission at - https://www.ftccomplaintassistant.gov/