Sent my 1st gen iPod nano off for replacement and haven't heard anything in nearly 5 weeks

So I sent off my iPod nano1st gen on the replacement program 4-5 weeks ago and I still haven't heard anything or the replacement delivery process hasn't went to the diagnosis phase. Shouldn't I know something by now or have confirmation that apple have received my iPod nano? Ay replies to this would be here helpful.

Thanks

Michael