New iPad app store error - security code invalid...

So I have the new iPad and as of today, I am unable to update apps or download any free ones or anything like that. It tells me to update my payment information, and when I put in all my info, it says the security code is invalid. I am 100% sure I am putting it in right. I googled it and it's apparently been an issue since like 2010, and all the answers I've found have said to do things I cant do, like set my payment method to "none". That isn't even an option for me. What do I do? I called apple and they had me email someone, but that was yesterday and I've received no answer.