Power cord issues!!

I have an older (white) macbook (I believe I bought it in 2009). I've since had to replace the power cord this past winter because my one year old sort of chewed / drooled too much into the old one. The newer power cord does not seem to fit right- its is sooo touchy and has to lay "just right" for it to work. I know its a different design than my old power cord... is this just sort of the nature of the beast with these new cords and old macbooks or is it just mine? It almost seems like its not the connection to the computer but if I wiggle the the cord itself it'll start or stop working.
Also, it cord where it hooks to the computer gets SUPER hot. Like REALLY hot. Like it could burn someone hot. I literally cannot even touch it when it gets like that (which isn't all the time).
I'm not exactly sure when I got the cord, in December I believe... if these are not typical problems of the cords can I still return it? I definitely don't have a receipt or the box or anything.