There are certain make-up schools that are MAC 'approved' - or that brand themselves that way. School of Makeup in Stockport uses MAC in their college kits and you get a MAC student discount card when you study there - although I have no clue how much involvement they actually have with MAC. As far as I know, you need to be a make-up artist already before you work for MAC, they don't train people from scratch and don't offer proper courses.
What area are you in? In the north west, there's School of Make up (which seems to be popular, lots of the working make-up artists round here have been there - tis expensive though, I'm still saving up!) also there's North West Media Make-up School and then in London there's Greasepaint (the best known I would say) and London Muse and London Academy of Freelance Make-up.
If you contact MAC they may be able to give you a list of approved courses (i.e. courses where they will give you a MAC student discount card once you're enrolled). They are very slow at getting back to you though so might be hard work to contact them.