Just pick up a replacement plug:If it's not covered, is this type of problem fixable?
http://www.homedepot.com/p/Leviton-15-Amp-125-Volt-Rubber-Grounding-Plug-R60-515PR-000/100011602 . There is even a video showing how easy . . . they do confuse things a bit by using a different plug with an extra wire.