iTunes gift card already been redeemed by another account

Has anyone else gone to redeem an iTunes gift card and been told that it has already been redeemed?

This happened to me last week. I scratched off the panel, entered the code and got the message 'The Gift Certificate or iTunes Card you entered has already been redeemed'.

When i reported this to Apple thay advised that they needed a picture/scan of the card and the shop receipt where it was purchased, I provided this information and was told there was nothing they could do to help. They know the acount that has used this code but still they will not investigate how this has happend.

So I loose my £25! I have gone back to them again and they have now offered to credit my account with 10 songs, so about £8.

How is this right!?