Mystery Car Damage

I just received an estimate on repairing my car. I thought it would be around $500, but it's almost $1500! I'm going to have to file this one. What happened and when? I don't know. When T and I walked out of Target and into the parking lot toward my car T said, "Somebody hit your mirror." As I got closer I saw there was more damage: 2 huge dents in the right door pillar. There were no mirror fragments on the parking lot, so this happened some other time or whoever hit my car picked up all of