I was making a large purchase at an auction I regularly attend, and sometimes I have to call ahead and let them know I'm going to make a charge. Before I could get someone on the phone, the merchant attempted to run the card, which came back "authorization required". I was told they would need to call me back on my cellphone to verify my identity, which they did. I was told the charge was approved. The merchant received the same message, "authorization required" on their terminal. When I called Diners Club again, I wa... read full review »