For The Love Of God, Please Help!

I heard this song in Forever 21 today and can't firgure out who it's by. It sounds like a girl band, definitely a woman lead singer, but I can barely make out anything she's singing because the background music sort of overpowers it.

I could only get, "and if you do, i told ya, i'd give it to you!"
and the very beginning, one girl goes, "five, six, five, six, seven, eight!" then they start playing.

the chorous is a bunch of girls chanting the lyrics.

Hope that's enough help. I've already tried googling it, nothing came up.'

PLEASE HELP!!

the go! team - huddle formation.

just in case you still check this website sometimes. registered just to tell you the title