Nope. You are S.O.L. with that saddle. I wouldn't blame the bike shop for not being sympathetic, considering the way people try to scam them for replacements. Besides, all they'd be able to do would be to duck tape it, too, so how helpful could they be?
If you broke a saddle, go buy a new one. You can't fix broken saddles. Not like that, anyway. You can duck tape it together, but it will never hold.