How did Corrie get so many ration cards

Now that Fred works at the Food office, Corrie visits his home in pursuit of ration cards. After praying silently, Corrie takes a chance and tells Fred that she needs one hundred cards for the Jews they are hiding in their home. After hesitating, Fred agrees to stage a robbery and appears a week later with bruises and cuts and the precious ration cards. Moreover, Fred plans to come each month, disguised as the meter man, in order to deliver more coupons and stow them in another tiny hiding place.