An ISO9000 feedback system would be good to see and Motability could see at a glance where problems lay and who’s not doing their job properly.
It’s seem to me like Motability think everything is rosy if looking at the Life Styles mag is anything to go by in how wonderful customers have been treated by said dealer but you have to look between the lines unfortunately and ask how many letters do you see referring to such problems as the OP has had and the answer to that is a big fat zero.
Motability works for me overall but I do have reservations too in how some parts of it work with test drives and incorrect deliveries of specified cars and like I said an ISO9000 system would do wonders to Motability if they really wanted to make thing better for their customers.