Ok, since my dad's credit cards are declined I bought a $15 iTunes Gift card to download a few games for my iPad. I finally got to update 30 apps, everything's good until I try to download GTA Chinatown Wars HD. It says a need a verification security code for my credit card I use, I enter it precisely as it is and it says "please enter valid security code". And I can't do anything..WTF? Can anybody help me please?