The idea of using facebook is that it reaches many and the companies don't like to see negatives so respond in such a way to give consumers a good impression.
Send an email and likely you get an apology and asked to return to place of purchase for refund or replacement, but yeah at least that makes them aware.
There is a craft beer facebook page for WA, the local brewers keep an eye on it and boy do they jump into action when someone posts a problem
