Hopefully you called them early this morning at BMA because I think they work Sat AM. I assume that you have the correct calipers and carriers. The rotors are really heavy at 315 x 28. I've done this conversion and bought the rotors from BMA for that conversion. Never had a problem with fit however. Did you check the part number you need against what was sent?
Mike Holbrook
Meridian, Idaho
1992 535im, 17", Euro M5 Throwing Stars 8's & 9's, FK-451 235/45s & 255/40s, M5 Sway Bars 25/20, Conforti chip, Lowes Ram Air, glass sunroof