For snow you want a smaller tire so the tire can move in the snow easier and maybe they only had 225 in stock at the moment. I hear so much on the All-season vs Winter tire thing and it's kinda hard to decipher unless you have personally experienced first hand with both tires in winter conditions. I have put all-season tires on my GTO and 135i but I haven't ran into any snow with them but I feel fairly confident that they will do well in the snow.
I know Tire Rack did a comparison on popular all-season vs winter tires and it was pretty insightful, so I would check them out for a review on them.
I'm not sure about the incorrect sizing refund but it would probably depend on how long the tires have been on and how many miles were put on them.