They have shadow stock so should hopefully ship next Wednesday. Doubt any company will ship before Christmas now.
Also, I would doubt they are fake as cannot see much cost saving in the effort to reproduce them and the packaging etc. but then 4 packs for £16 hmmm, does sound dubious seeming as they are around £8 a pack of 2.
Wex photographic have them in stock for £8. I paid £5 for next day delivery which arrived today. (Broke a set yesterday and going away over xmas so want spares) but normal postage is cheap enough.