St. Louis based grocery store chain Schnucks now believes 2.4 million credit and debit cards have been compromised. The company first learned on March 15 of questionable activity and began an investigation on March 19. Schnucks said it found the problem on March 28 and executed a plan to contain it within 36 hours. According to the company, from December 2012 to March 29, 2013, 79 of their 100 stores, including Washington, were affected by credit and debit card thieves. Schnucks has set up a call line for customers to use for any questions. The number is 1-888-414-8022.