I haven't had that particular beer, but I'd say you probably got a bad six pack. I've never tasted anything plastic-like in any of the ESBs I've tried.
Next: Lamebic '15, Irish Red
Fermenting: Saison, Petite Saison, 100% Brett B. Red, 100% Brett L. Kriek
Souring/Funkifying: Brett C Old Ale, Lamebic '14, Flanders Red, Flanders Pale, Oud Bruin, Session Kriek
Bottled: IIPA, APA, American Amber, Robust Porter, Strong Mild, 80/-, Gose, Lichtenhainer
Bottle Cellar: Brett B Tripel, Brett C Barleywine, Lamebic '11, Quad, Tripel, Brett C Bitter, Wild Cider, Sour Stout, Wee Heavy