Disappointing but not surprising for Diners Club, considering its confused management and disdain for loyal customers. You would think with its rapidly aging customer demographic, it would embrace a young, traveling business person with a high monthly spend who pays on time.

If the situation is as the person described it, then why would anyone want to use a Diners Club card? The person was approved and has been using the card legally and appropriately. To be notified through a credit decline at a merchant is insulting and totally unprofessional on the part of Diners Club.

If I were the user, I would complain LOUDLY to Diners Club management in Chicago (773-380-5160). I would also complain that Diners is discriminating against him based on age, which may be illegal and a violation of the Equal Credit Opportunity Act. He would have both federal and state recourse, as many states have similar anti-discrimination laws.

Or he could file a class-action suit enjoining other victims of Diners Club bizarre credit policies. Ohh wait, Diners Club specifically prohibits you from joining a class-action suit against it.