You might be able to take the train or fly, but only with the lowest class of seats. There might be something punitive in this, but another aspect of it is that

You might be able to take the train or fly, but only with the lowest class of seats. There might be something punitive in this, but another aspect of it is that you don't want to sell expensive things to people with bad credit. There are myriad ways people try to get out of paying for things -- returning them, cancelling last minute, filing complaints -- that leave the merchant holding the bag even after a sale is seemingly complete.