Tire Bead problems of the 1996 Dodge Caravan

Purchased the tires on April 24,2004 from sears. I had my fiance take my vehicle back to sears approximately a month or month and a half ago and reported to them that there was a problem with the tires and all they did was rotate all 4 tires for me. Then tonight 12/4/04 we were driving home from outting with my children and driving 55m. P. H. And had to pull of the highway for a flat tire. Upon further inspection of the tire you could see where it looks to be the beading seperated. We are going to take the tire and the vehicle with the other 3 tires back to sears tomorrow, 12/05/04 and see what they are going to do about the problem with the tires. Tires are manufactured by michelin and are road handler 215/65s16.