I've heard "plug it up" too, from a friend in S. Carolina. And for what it's worth, I teased him about it too - never hear that phrased that way over here on the left coast. I also teased him for calling shopping carts, "buggies". But the teasing was friendly, he didn't mind and just teased me right back for calling pop, "soda". (Which is, of course, totally backwards.) ;-)
I thought it was a harmless/friendly joke, too bad the original poster took it as an insult.