I've had my order cancelled too. Looks like it was actually Barclaycard that turned it down (probably - haven't actually spoken to a human there, just a machine). I had one 15% discount code, and no cashbacks or anything else.
It looks to me like it is the credit card companies declining the transactions, but there's no excuse for Nokia to not honour the discount codes.
Are any of you with cancelled orders using shipping addresses which are different to your billing address? I've had things where my bank calls me after I've ordered something online which is delivered to a different address.
Tesco, my credit card company called me 60 seconds after declining to ask me if it was a real transaction then told me to call Nokia and tell them to re-put the credit card transaction.
After 45 minutes on hold not getting through to anyone on phone, I see an email saying my order was cancelled due to an error with credit card and told me to place a new order. So I have placed a new order. Hopefully this goes through. Hope it doesn't add too much lag on getting the order in.