Bri - I think exactly the same. As I mentioned to the chap at TileFixDirect what if I was in the same situation but from up north? Not really the sort of customer service I'd expect tbh.
3_fall - yes I'm ex Royal Engineer. I do like to maintain the same brand where I can if I can get all the products there.
AliGage - to be fair to TileFixDirect it does state on their site the minimum orders required for each size of sheet however you would assume that if you have already hit that quota it wouldn't be an issue to have singles. The 10mm sheets have a minimum order of 10, but once you hit that you can add on 1,2, etc as you wish.
In all honesty I would normally just send the whole lot back but tbh its 3 sheets and by doing that it will put back my schedule. Plus I've already sorted the shower tray and drain in the wetroom.
I'm surprised the Orbry rep has as of yet not replied either on this thread or via PM.