Hi Barbara,
Well done on your award. The conversation you describe with DWP sound like a bit of a try on. It seems odd that DWP would 'offer' only standard mobility, and then because you disagreed would then rethink. I suspect, rather cynically, that DWP actually always believed that enhanced mobility was appropriate but maybe they could get away with just a standard award?
I think you need to query the date and ask for a full explanation as to why the date is not as expected. You could certainly still appeal on the basis of wrong date. After all the difference seems to be around 6 months, and this could be several hundred pounds of benefit. The only possibility I can think of, is if you were sent a review form early, so it would be ready for when your review date or end date which would be later on on the year.
LL26
Nothing on this board constitutes legal advice - always consult a professional about specific problems 
