I've just had the same problem. I phoned a few dealers. One wanted £20. one said it was free, but I'd need to take the ownership papers in. I walked into another one and the service department just gave me the code.
If you look at www.renaultforums.co.uk , there's a thread there where someone is offering codes for free. just send them the vin number and they'll give you the code.
Have you checked the batteries in the key fob?
Nick Pick, February 2008