The Man from the Diners' Club(1963)

Meek credit card company clerk Ernest Klenk is feeling the pressure of demanding coworkers, new computers, and an upcoming wedding. This stress leads to a big mistake -- the accidental approval of a credit card for mobster Foots Pulardos, who is planning to flee to Mexico with his girlfriend, Sugar Pye, to avoid criminal charges. When Klenk tries to fix his mix-up, he gets dangerously involved in Foots' scheme.