Name that song.

[apex204]

My housemate is desperately trying to find out the name of a song. It's from about 10 years ago and by a three-piece girl band (this much he remembers). At the start of the track it's like an answerphone recording..

'Hi, we're not here right now, but if you leave your name and number, we'll get back to you...'
And 'back to you' is harmonised by the group. Any ideas?

[Mortartube]

Yep, that's the one.

https://www.youtube.com/watch?v=yWSneLtcVSU