Itunes gift card balance

I have looked all over to try to find where I can see my iTunes gift card balance on my iTunes on my computer. And I cannot find it. Nothing is there that people say is there. There is no balance place to click or anything. I am very confused and just want to purchase music. I redeemed 2 gift cards and it let me but nothing is showing anywhere and it will only default and pay with my credit card which I don't want to do.