If you bought after June 27th oh well... Tough break but you pay your money and you take your chances, you were a greedy short term arb player, you made your bed, now it is time to sleep in it, there was always the chance the gov't was going to axe the deal, if you were an investor BEFORE the takeover announcement then you can't be overly discouraged to be still owning the stock for the long term.
Very little free money handed out in the market....now the risk side of the risk/reward play if you bought over $20 is now going to play out. Time to take your medecine.