general problems of the 2010 Nissan Versa

I have ordered a pair of tires from discount tire direct and after I put them on the car, I thought they are ok, so I ordered another pair. Few months later one of the tires developed un-round shape and it was torn from the inside. I have contacted discount tire direct, and they forced me to pay another $14, and I returned the bad one and they sent me another one same make and model. This week I have the same problem again. One of the tires developed that un-round shape again. Both incidents happened on our family car where my little kids are inside the car. That’s unacceptable; if any of these deformations would have caused the tire to explode, that would have caused unacceptable harm to my family. This product threatens the well being of my family. At this time I no longer accept this product at all and I demand a full refund for all the money I have paid so far. I have all receipts, photos for the first tire, photos for the second tire, and all 4 tires. Note: the tires writen on them milestar ms932 88h nss-01-12f0.