Desperately need a single song on iTunes but don't have a credit card!!!!!?

I'm singing a song THIS FRIDAY at school so I need a karaoke version. I managed to set up an iTunes account without a credit card but now I need this song. Hannah Montana - I'll always remember you acoustic version. I checked and it is �0.79 so its not much so if anyone knows where I can get a pound code or a single song credit or anything that would be great. And p.s, don't say one of those ones where you have to follow on twitter or facebook or anything to get it because i don't have any social networking site profiles.