Yahoo! Password Required
Recently, last two weeks or so, I've been getting a popup on my Mac and iPhone telling my that my Yahoo password is required. I follow the prompts, enter my password, get an email from yahoo my account has been signed in from such and such device and everything seems fine. Then a day or so later it wants me to do the same thing again and again...
Apple told me to contact Yahoo. I can not find anyway to contact Yahoo.
MacBook Pro (Retina, 15-inch, Late 2013), OS X Mavericks (10.9.2)