Gift card balance

You can't check the value of a card without redeeming (and therefore using) it. If you've scraped off the card's code try contacting iTunes Support, they will want to see images of the front and back off it and its receipt : http://www.apple.com/support/itunes/ww

If the card hasn't been redeemed (if it has it's used and empty) and if it doesn't have its value written on it, you would need to redeem ( and therefore empty) the card to know its value

i cant check balance with number i scratched off back

duh