My online payment was declined and it says i enter the wrong security number when i didn't. help!?

My Debit card have been upgraded recently. I was sent a new debit card. I purchased some Apps in AppStore and saying that i have an outstanding bill of USD$0.99. I went to ATM and realised that there're still sufficient balance in it and went back to make the payment. Yet when i logged into AppStore they decline my security number saying i have entered an invalid security number. I've tried both card's security number and none work. I am unable to purchase any application now as it'll tell me that i have a billing problem. Help!!! I have no idea if it is because the card is faulty.