I was on yahoo personals and have been scammed by goodboy_432 and I have a current one online charmingstan001

I want to know how I contact Yahoo to report them. They found me through Yahoo personals and they lived in United states but now living abroad because of business. How do I contact Yahoo Personals to inform them of Scammers from Nigeria, Canada and England. Mine was on the Dr. Phil show this Cole Bash person the first time but beware of goodboy_432 and charmingstan001 these men are scammers.