Hi
I have just sent an e-mail about this, but I am happy to repeat the advice here, and I am sorry about earlier.
That is the helpline, but the employer is the only one who can contact them, and sometimes they take a while to get back.
It is true that you can't ask about your application until it has been outstanding for 14 weeks, but your employers can ask (weird, huh?). I don't think Chris said that if you call UKBA they would withdraw your application, but if you ask for your passport back then they will withdraw it (which is where I think the confusion has arisen).
If your employer call that number then they will be sent a form which they have to fax back to get the info on your status.
Vicky