OXFORD, Mich. -Meijer issued an alert to customers Wednesday that diesel fuel sold at their Oxford store may have been contaminated with unleaded gasoline.The problem happened during a fuel delivery when unleaded fuel was mistakenly added to diesel fuel. Customers who purchased diesel fuel from Sunday July 14 to Tuesday July 16 at the location at 900 N. Lapeer Road are asked to contact Meijer at 800-543-3704.