OK.
When you reserve a new home you normally are required to sign a form which details the plans you have seen and that is what you are buying. Did the house type plan (and revision) you were shown have an en-suite bathroom?
The on site sales brochure must surely have had this house type clearly shown with an en-suite.
This is obviously important and was a prime consideration for you when you reserved.
Now the fact that Miller have two versions online one with an en-suite and wardrobe and one with out either demonstrates that these have been cut to maximise profits by reducing production costs.
However, without an en-suite presumably the houses would sell for less.
I suspect that the non en-suite wardrobe version is the social housing version for this house type.
Whatever you do, do not exchange contracts until you are 100% sure your home has an en-suite with or without the wardrobe.
If it is not to have an en-suite I wouldn't buy it.
Most homes have en-suite and subsequent buyers would expect this.
I doubt Miller would reduce the price low enough to fully compensate this.
I would also not wish to deal with a housebuilder who is as it looks to me, acting in such an underhand and deceptive manner.
No en-suite no sale is my advice and you will get 100% of your reservation fee back and any other expenses you have incurred plus £250 for "inconvenience if you need to complain using the
Consumer Code for Home Builders Adjudication Scheme.