I don't think I've ever under-cooked meat, I definitely have never under-cooked chicken. I do tend to over-cook it sometimes because of that though, but it's not too bad, just a bit dry. And why didn't you send the chicken back?
I love cooking too, but being the lazy ass I am, I don't do it as much as I would like. I'm actually thinking of pursuing a cooking career and go to a culinary school of some sort, but I'm not sure how that will turn out, cause of the money and all.