Since Hornby switched to having a 3rd party company handling their warehousing and distribution they have had far less say in where their models end up. They appear to get their own retail supplies via that same company.
I wasn't wishing to put the evil eye on your purchase, simply to alert others who may have followed your earlier link. Jadlam Racing have history which means that you can never count on getting the model you order from them until it's actually in your hand. I'm assuming you've used PayPal. If it doesn't appear, you should at least see your money back in the fullness of time, even if you need to claim through eBay. Hopefully everything will be straightforward for you.