What is the version of software running your iPod? I think you need version 2.0 or higher to run apps. Even then check the specs for the apps in the iTunes Store to ensure they are compatible with the touchs software version. Apps that require version 3 software will not transfer to an iPod with version 2 software.
Oh also I put $45.00 on my ipod with Gift cards and it still says I need a payment plan? What's the deal with that?
I'm going to guess you are in Canada. Apple claims there is some laws or trade rules that prevents them from using store credits for software purchases in the Canadian iTunes Store. You need a credit card set up to purchase iPod touch software updates and Apps. This still burns me since I use my credit card to purchase these giftcards that can not be use to purchase the same things. The credits will still work for music and video purchases.
64GB iPad 3, 32GB iPhone 4, 1G 16GB touch, 4G & 6G Silver 16GB nano, 5G 60GB iPod, 1G AppleTV, 2G ATV, 2.5GHz 17" MacBook Pro