Personally, I do wonder if there is more to the story, but for everyone complaining what Diner's Club did is unfair, it should be emphasized that Diner's Club did give the OP an out by submitting income verification, etc, but the OP said that he does not want to do it.

That is his choice, just as it is DC's choice to be concerned about him worthiness as a customer and want to protect themselves from possible default situation without additional documentation.

BillJ