Hi my name is ***** ***** I will be the expert working with you today to help and resolve the problem you have posted.
I am sorry to hear that you are having such trouble. I will try my best to help you out and resolve the problem as quick as possible.
No company like yahoo or google contact customer personally or send warning emails or any popup screens on your computer or smartphones.Email servers are very safe and secure and no one can hack into it that is why there are many scams who claim to be Microsoft Google or Yahoo by sending popcall screen and warnings with phone number to call or they call you. You get into trap and they extort $300 to $500 and all of a sudden dissappear and you cannot catch or report them in that case be alert and try to be in touch with the trusted company by confirming they have a business online for more the 5 years and you have a number to call and reach them. I believe that answered your question, let me know if you have any question.
download and run adwcleaner from the link below it will fix the popup