Puts you through to a sex line!
Na not really, its the direct way to Orange's retention team who will fall over backwards to keep you with them.
No need to blag your way through about 4 menus on the phone, then have a conversation of about 5 minutes with customer service or upgrades.
What I do is about a week before, I speak to upgrades checking phones and deals so the presume I have been given the number at that point