PS Canon approved my cashback claim. It hasn't been paid yet but confirmed. Time to sell my 600D!
it's on the winter cashback page in the table at the bottom down as COSTCO WHOLESALE UK LTD
Called them the guy was lying they sold loads this morning so just went out of stock. I told him it's been out of stock for few days actually. Then he was like oh we sold them all at xmas as price was good. They will get more stock but not at that price. To me seems like they only did it to get some free advertisement. I wouldn't be buying from them even if stock returns.
or even here: http://www.canon.co.uk/where_to_buy/for_home/
Just checking... but can't see Costco on the list (under a different name perhaps?) http://www.canon-winter-2015-uk.sales-promotions.com/gallery/pdf_links/winter2015ts-cs-uk-list.pdf