OK. Bit naughty of the dealer maybe, but as you say, too nice and scarce a car to miss perhaps.
Down to the nitty-gritty. Read the error code or get it read, and proceed from there. Probably not so much of a problem; always soluble in any event. Lots of info and advice available here when your membership "greenness" allows you access.
If your MGOC membership number is not yet through (can take some time), PM Tim, and tell him the the application has been made and is being processed. That may help.