After following the instructions from hass, I placed an order and got a confirmation email from Nokia that included this text:
PS: If anyone is making a purchase using the method described by Hass, please sign up using this referral code:
http://www.topcashback.co.uk/ref/eiffel

If Hass posts his own referral code, I'll remove this one because Hass is the one who found the discount.

Regards,
Roger

[ edit: Hass is happy for people to use either link. Here's his: http://www.topcashback.co.uk/ref/hass80 ]