You cannot purchase discontinued foods such as Wheatables because the manufacturer does not produce them anymore, hence they are not available in the market. Online retailers such as Amazon and Kmart also report that Wheatables are currently out of stock, as of 2015.
Keebler introduced Wheatables in 1988 with the aim of offering customers an alternative to fried snacks but discontinued the brand in July 2014, which consisted of Toasted Honey Wheat, Original Golden Wheat and Wheatables Nut Crisps varieties. The company had previously discontinued another variety, Seven Grain. You can still purchase other discontinued foods shortly after the manufacturer stops producing them as some retailers may still have them in stock.