How can I overide the immobiliser on my Clio Dynamique 02 plate?

The key fob for the car packed in today leaving me stranded at home! I have contacted renault only to be told that a new key will be £140+vat and i'll have to wait 10 to 12 days for it! Toyed with the ebay idea but been told that won't work as the keys can only be programmed once!

I just need to know if there is a way of turning off the immobiliser so i can use my car!? and if renault are correct in what they say about the keys or are they just after my money???

Thanks in advance