I just recently did this same exact process and I was able to get a replacement free of charge, but with some hardship involved
1. Wheel has no visible signs of dent, curb, or looks out of round
2. New 225m's obviously has a new design compared to the old one
3. Car is still under warranty til Mar 2014
See photos of the New 225m's and note the bigger lip and strengthened barrel design and maybe you can show these pictures and prove that the old style 225m wheels have a faulty design and you could get BMW UK to replace it free of charge
My photos and videos are at http://www.photobucket.com/19inch
Hope this helps!