change a credit card for family account

It is asking me to know the security code for my old card, that i threw away. How the helll do i have 2 step auth on and it asks me for the OLD card info i am trying to replace for my family to use. Another example of poor design in the actual products being used, but i am glad my iPhone 6 plus is as thin as it is, but would be nice if it actually work constantly with the products you create... Maybe you should have the community build everything but the hardware for you, i bet you would get better products out there.... SO HOW THE **** DO I CHANGE MY FAMILY CREDIT CARD TO A NEW ONE......... I MIGHT BE MOVING ON FROM A APPLE SOON HERE, WHATS EVEN BETTER IS I HAVE A ITUNES GIFT CARD BALANCE I NOW CAN NOT USE DUE TO THIS ISSUE. THANKS AGAIN FOR SOMEHOW NOT THINKING THAT WHEN A CARD IS BEING REPLACED THAT INFO IS NOT NEEDED, ALSO HEADS UP 2 STEP AUTH ALREADY VERIFIED WHO I AM SO STOP FKING ASKING....