iTunes Help!!

[bodhi]

Help!! iTunes is so awful to use that I need to ask someone that's used it before.

I got the iPod touch at xmas and i've loaded loads of my CDs onto iTunes and have them on my iPod. I have £25 worth of credit on Itunes now, but when I bought something direct from my iPod it came off my debit card.

I now want to spend the £25 of credit, but when i go to buy something it doesn't mention it and it does show my debit card details. How do I make it use the iTunes credit first before just taking the money from my debit card??

Thanks.