Now paid. Thanks to the OP.
Just an update, this has now validated.
I queried this with Quidco and received this reply today: "thanks for getting in touch. The 30% was not a mistake, it was just a very good offer. You cashback has tracked at the correct amount so there should be no problems."
yea thought 30% must be a mistake
Nokia's cashback has been changed to 5% on Quidco. Wonder if that means that all those that ordered thinking they would get 30% will now only get 5? 30% does seem extraordinarily high for a hardware only purchase and sounds more like a slip-up to me.