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.
Up Next: Flanders Red, Belgian IPA
Primary: Malt Liquor, Wild Cider, English Cider
Souring: Lamebic, Brett. C. Old Ale, Sour Stout, Brett C. Wild Bitter
Polypinned: English IPA
Bottled: Sticke Altbier, Doppelsticke Altbier, Weizenbock, Berliner Weisse, Spruce Brown Ale, English Summer Ale, Coniston Bluebird Bitter Clone v1.5, Best Bitter, Spiced Winter Warmer
In the "cellar": Brett B. Tripel, Quadrupel, Tripel, Brett C. Oaked English Barleywine, Lamebic