Not true. You have to do business with a company not simply call them. There is not "getting around" The Do Not Call list since it only applies to legitimate companies that are subject to American law. A scam call is almost certainly calling from outside the US using the Internet to fake a US area code.
Same... Rings once, no message. Heard if your curious and return the call, then that's how they get by the 'No Call' list. Your calling them, so they in turn can call you back.
#Do Not Call Them Back!!!!