Received email this afternoon confirming my downgrade and informing that I could apply for a refund for the difference for travel in a lower cabin for tickets issued by KLM by following an attached link. I duly complied providing the information as suggested , this gave me the option of cancellation or contacting KLM as cancellation is not an option I followed the contact link this took me to Air France unfortunately without the ability to apply for a refund for downgrading . I telephoned KLM also quoting EU261/2004 but they could not help only suggesting that I followed the link despite my reservation on it's functionality looks like I will have to explore further .