Does anyone know who to contact at these companies if I plan to make a large purchase with my card? I'm getting ready to buy a new car and the dealership allows 10% payment with CC. Only problem is whenever I make a large purchase with these cards, it always gets declined. I just want to prevent it from being declined. I specifically called Citi last time and told a representative about the upcoming large purchase and I was told she noted it in the account and it should go through. Next thing I know, the card is declined.

Any information including which department to contact (I'm assuming fraud department) and telephone numbers would be much appreciated. Thanks