What does the bearing look like. Is it all loose and sloppy?
How could it be the springs as you just had them installed. What kind of mileage could you have on the car with those springs, 75 miles?
If you don't get any satisfaction with BMW NA, I would take them to small claims court. Usually (depends on state) $50 filing fee, you represent yourself (bring your bearing with you if it looks like above) and make your case.
Did they explain why the wheel bearing would give you a DSC and ABS warning lights?