I disagree that they are a bad choice for OEM. I do not disagree that they are a bad choice for you. All MINIs with 16 & 17 inch wheels come with runflats. There was no other choice. World wide most MINIs with 16 and 17 inch factory wheels are MCS cars with no spare.
Did you rotate the tires? That will extend the life as MINIs are very nose heavy. You should consider that for your next set of tires. Every 10k miles or so should do. Be advised that the factory recommends against rotating the tires because you have to do it often to prevent tread separation. If you complained about the ride the dealership may have lowered the tire pressure. That could also cause premature ware, but it will improve the ride.