Yes, 3 days of frustration and a delay of a needed purchase due to Citi's VAN being unavailable. Correct me if I'm wrong, but I use Citi over Discover because with Citi, we can specifiy an amount and expiration date for each individual VAN. Discover lacks these options, and a merchant can continue to use the number for future purchases. The VAN numbers don't expire until the card expires. To delete previous VAN numbers, one has to go through the trouble of calling Discover to request it. For me, this negates the ease and security of a VAN.
