Stone or sand in the ground beef

Very disappointing I've been shopping at oxford on the bluff since they opened. I recently purchased a tray of ground beef in bulk and after it was cooked noticed that the were sand or stone i can’t really say but my goodness that feeling on your teeth. I had to throw the whole pot of food out because even both my kids noticed the same thing. I don’t even trust the rest in the freezer. I don’t have my receipt so i guess this tray is gone to waste in this economy where food is so expensive. I now have the thought that food or the raw meat fell on the floor and it was picked up n packing continues or a dirty item was used to clean the thing that grinds this meat my mind is just racing.