Tire Bead problems of the 2004 BMW X3

Since buying my car, I had issues with the flat tire monitor indicator light coming on. I continually checked the pressure of all 4 tires and ventually, this past September, after only 1,845 miles, had to have a tire repaired (cost $15). The diagnosis was simply a leaking bead. At 2,651 miles, another tire suffered irreparable damage caused. Also, from a leaking bead. A replacement tire will need to be ordered ($217+), and since there's no spare with my Mini, I need to make other transportation arrangements. I am extremely disappointed that leaking beads, a very rare problem with any other car but this one, continue to be problematic with my Mini being so young. I have checked the Mini owner's manual and the distance and speed driven with the run flat pirelli tires were well below both the speed and distance limits indicated. I feel strongly that both Mini and pirelli are seriously deficient in this circumstance. The actual mounting of these tires was obviously not done very well, nor does the advertised capabilities of the run flat pirelli eufori tire seem to be reasonable.